Computer Fundamental 1
COMPUTER FUNDAMENTAL 1. UNIVAC is A) Universal Automatic Computer B) Universal Array Computer C) Unique Automatic Computer D) Unvalued Automatic Computer
2. The basic operations performed by a computer are A) Arithmetic operation B) Logical operation C) Storage and relative D) All the above
3. The two major types of computer chips are A) External memory chip B) Primary memory chip C) Microprocessor chip D) Both b and c
4. Microprocessors as switching devices are for which generation computers A) First Generation B) Second Generation C) Third Generation D) Fourth Generation
5. What is the main difference between a mainframe and a super computer? A) Super computer is much larger than mainframe computers B) Super computers are much smaller than mainframe computers C) Supercomputers are focused to execute few programs as fast as possible while mainframe uses its power to execute as many programs concurrently D) Supercomputers are focused to execute as many programs as possible while mainframe uses its power to execute few programs as fast as possible.
6. ASCII and EBCDIC are the popular character coding systems. What does EBCDIC stand for? A) Extended Binary Coded Decimal Interchange Code B) Extended Bit Code Decimal Interchange Code C) Extended Bit Case Decimal Interchange Code
D) Extended Binary Case Decimal Interchange Code
7. The brain of any computer system is A) ALU B) Memory C) CPU D) Control unit
8. Storage capacity of magnetic disk depends on A) Tracks per inch of surface B) Bits per inch of tracks C) Disk pack in disk surface D) All of above
9. The two kinds of main memory are: A) Primary and secondary B) Random and sequential C) ROM and RAM D) All of above
10. A storage area used to store data to a compensate for the difference in speed at which the different units can handle data is A) Memory B) Buffer C) Accumulator D) Address
11. Computer is free from tiresome and boardoom. We call it A) Accuracy B) Reliability C) Diligence D) Versatility
12. Integrated Circuits (Ics) are related to which generation of computers? A) First generation B) Second generation C) Third generation D) Fourth generation
13. CD-ROM is a A) Semiconductor memory B) Memory register C) Magnetic memory D) None of above
14. A hybrid computer A) Resembles digital computer B) Resembles analogue computer C) Resembles both a digital and analogue computer D) None of the above
15. Which type of computers uses the 8-bit code called EBCDIC? A) Minicomputers B) Microcomputers C) Mainframe computers D) Super computer
16. The ALU of a computer responds to the commands coming from A) Primary memory B) Control section C) External memory D) Cache memory
17. Chief component of first generation computer was A) Transistors B) Vacuum Tubes and Valves C) Integrated Circuits D) None of above
18. To produce high quality graphics (hardcopy) in color, you would want to use a/n A) RGB monitor B) Plotter C) Ink-jet printer D) Laser printer
19. What are the stages in the compilation process? A) Feasibility study, system design and testing B) Implementation and documentation C) Lexical Analysis, syntax analysis, and code generation D) None of the above
20. Which of the following IC was used in third generation of computers? A) SSI B) MSI C) LSI D) Both a and b
21. The main electronic component used in first generation computers was A) Transistors B) Vacuum Tubes and Valves C) Integrated Circuits D) None of above
22. A dumb terminal has A) An embedded microprocessor B) Extensive memory C) Independent processing capability D) A keyboard and screen
23. One millisecond is A) 1 second B) 10th of a second C) 1000th of a second D) 10000th of a second
24. The output quality of a printer is measured by A) Dot per sq. inch B) Dot per inch C) Dots printed per unit time D) All of the above
25. Which of the following was a special purpose computer? A) ABC B) ENIAC C) EDVAC D) All of the above
26. What was the computer invented by Attanasoff and Clifford? A) Mark I B) ABC C) Z3 D) None of above
27. Which of the following storage devices can store maximum amount of data? A) Floppy Disk B) Hard Disk C) Compact Disk D) Magneto Optic Disk
28. Which computer was considered the first electronic computer until 1973 when court invalidated the patent? A) ENIAC B) MARK I C) Z3 D) ABC
29. A physical connection between the microprocessor memory and other parts of the microcomputer is known as A) Path B) Address bus C) Route D) All of the above
30. High density double sided floppy disks could store _____ of data A) 1.40 MB B) 1.44 GB C) 1.40 GB D) 1.44 MB
31. A high quality CAD system uses the following for printing drawing and graphs A) Dot matrix printer B) Digital plotter C) Line printer D) All of the above
32. Which of the following is not an input device? A) OCR B) Optical scanners C) Voice recognition device D) COM (Computer Output to Microfilm)
33. The accuracy of the floating-point numbers representable in two 16-bit words of a computer is approximately A) 16 digits B) 6 digits C) 9 digits D) All of above
34. In most of the IBM PCs, the CPU, the device drivers, memory, expansion slots and active components are mounted on a single board. What is the name of the board? A) Motherboard B) Daughterboard C) Bredboard D) Fatherboard
35. In most IBM PCs, the CPU, the device drives, memory expansion slots and active components are mounted on a single board. What is the name of this board? A) Motherboard B) Breadboard C) Daughter board D) Grandmother board
36. Magnetic disks are the most popular medium for A) Direct access B) Sequential access C) Both of above D) None of above
37. A technique used by codes to convert an analog signal into a digital bit stream is known as A) Pulse code modulation B) Pulse stretcher C) Query processing D) Queue management
38. Regarding a VDU, Which statement is more correct? A) It is an output device B) It is an input device C) It is a peripheral device D) It is hardware item
39. A modern electronic computer is a machine that is meant for A) Doing quick mathematical calculations B) Input, storage, manipulation and outputting of data C) Electronic data processing D) Performing repetitive tasks accurately
40. When was vacuum tube invented? A) 1900 B) 1906 C) 1910 D) 1880
41. Which of the following produces the best quality graphics reproduction? A) Laser printer B) Ink jet printer C) Plotter D) Dot matrix printer
42. Computers with 80286 microprocessor is A) XT computer B) AT comptuers C) PS/2 computer D) None of above
43. An application suitable for sequential processing is A) Processing of grades B) Payroll processing C) Both a and b D) All of above
44. Which of the following is not processing? A) Arranging B) Manipulating C) Calculating D) Gathering
45. The digital computer was developed primarily in A) USSR B) Japan C) USA D) UK
46. Software in computer A) Enhances the capabilities of the hardware machine B) Increase the speed of central processing unit C) Both of above D) None of above
47. Today’s computer giant IBM was earlier known by different name which was changes in 1924. What was that name? A) Tabulator Machine Co. B) Computing Tabulating Recording Co. C) The Tabulator Ltd. D) International Computer Ltd.
48. Before a disk drive can access any sector record, a computer program has to provide the record’s disk address. What information does this address specify? A) Track number B) Sector number C) Surface number D) All of above
49. The arranging of data in a logical sequence is called A) Sorting B) Classifying C) Reproducing D) Summarizing
50. What is the responsibility of the logical unit in the CPU of a computer? A) To produce result B) To compare numbers C) To control flow of information D) To do math’s works
51. Abacus was the first A) Electronic computer B) Mechanical computer C) Electronic calculator D) Mechanical calculator
52. If in a computer, 16 bits are used to specify address in a RAM, the number of addresses will be A) 216 B) 65,536 C) 64K D) Any of the above
53. Instructions and memory address are represented by A) Character code B) Binary codes C) Binary word D) Parity bit
54. The terminal device that functions as a cash register, computer terminal, and OCR reader is the: A) Data collection terminal B) OCR register terminal C) Video Display terminal D) POS terminal
55. A set of flip flops integrated together is called ____ A) Counter B) Adder C) Register D) None of the above
56. People often call ______as the brain of computer system A) Control Unit B) Arithmetic Logic Unit C) Central Processing Unit D) Storage Unit
57. Which is used for manufacturing chips? A) Bus B) Control unit C) Semiconductors D) A and b only
58. The value of each bead in heaven is A) 1 B) 3 C) 5 D) 7
59. The first computer introduced in Nepal was A) IBM 1400 B) IBM 1401 C) IBM 1402 D) IBM1402
60. Mnemonic a memory trick is used in which of the following language? A) Machine language B) Assembly language C) High level language D) None of above
61. Instruction in computer languages consists of A) OPCODE B) OPERAND C) Both of above D) None of above
62. Which generation of computer is still under development A) Fourth Generation B) Fifth Generation C) Sixth Generation D) Seventh Generation
63. A register organized to allow to move left or right operations is called a ____ A) Counter B) Loader C) Adder D) Shift register
64. Which was the most popular first generation computer? A) IBM 1650 B) IBM 360 C) IBM 1130 D) IBM 2700
65. Which is considered a direct entry input device? A) Optical scanner B) Mouse and digitizer C) Light pen D) All of the above
66. A set of information that defines the status of resources allocated to a process is A) Process control B) ALU C) Register Unit D) Process description
67. Each set of Napier’s bones consisted of ______rods. A) 5 B) 9 C) 11 D) 13
68. BCD is A) Binary Coded Decimal B) Bit Coded Decimal C) Binary Coded Digit D) Bit Coded Digit
69. When was the world’s first laptop computer introduced in the market and by whom? A) Hewlett-Packard, 1980 B) Epson, 1981 C) Laplink Traveling Software Inc, 1982 D) Tandy Model-200, 1985
70. From which generation operating systems were developed? A) First B) Second C) Third D) Fourth
71. The first firm to mass-market a microcomputer as a personal computer was A) IBM B) Super UNIVAC C) Radio Shaks D) Data General Corporation
72. How many address lines are needed to address each machine location in a 2048 x 4 memory chip? A) 10 B) 11 C) 8 D) 12
73. Properly arranged data is called A) Field B) Words C) Information D) File
74. A computer consists of A) A central processing unit B) A memory C) Input and output unit D) All of the above
75. Why are vacuum tubes also called valves? A) Because they can amplify the weak signals and make them strong B) Because they can stop or allow the flow of current C) Both of above D) None of above
76. John Napier invented Logarithm in A) 1614 B) 1617 C) 1620 D) None of above
77. An integrated circuit is A) A complicated circuit B) An integrating device C) Much costlier than a single transistor D) Fabricated on a tiny silicon chip
78. What type of control pins are needed in a microprocessor to regulate traffic on the bus, in order to prevent two devices from trying to use it at the same time? A) Bus control B) Interrupts C) Bus arbitration D) Status
79. Where as a computer mouse moves over the table surface, the trackball is A) Stationary B) Difficult to move C) Dragged D) Moved in small steps
80. Which of the following is used as a primary storage device? A) Magnetic drum B) Hard Disks C) Floppy D) All of above
81. Multi user systems provided cost savings for small business because they use a single processing unit to link several A) Personal computers B) Workstations C) Dumb terminals D) Mainframes
82. What are the three decisions making operations performed by the ALU of a computer? A) Grater than B) Less than C) Equal to D) All of the above
83. The word processing task associated with changing the appearance of a document is A) Editing B) Writing C) Formatting D) All of above
84. Nepal brought a computer for census of 2028 BS. This computer was of A) First generation B) Second generation C) Third generation D) Fourth generation
85. Algorithm and Flow chart help us to A) Know the memory capacity B) Identify the base of a number system C) Direct the output to a printer D) Specify the problem completely and clearly
86. Which statement is valid about computer program? A) It is understood by a computer B) It is understood by programmer C) It is understood user D) Both a & b
87. The difference between memory and storage is that memory is _____ and storage is __ A) Temporary, permanent B) Permanent, temporary C) Slow, fast D) All of above
88. When was Pascaline invented? A) 1617 B) 1620 C) 1642 D) 1837
89. Which of the following statement is valid? A) Lady Augusta is the first programmer B) Ada is the daughter of Lord Byron, a famous English poet C) ADA is a programming language developed by US Defense D) All of above
90. A compiler is a translating program which A) Translates instruction of a high level language into machine language B) Translates entire source program into machine language program C) It is not involved in program’s execution D) All of above
91. What is required when more than one person uses a central computer at the same time? A) Light pen B) Mouse C) Digitizer D) Terminal
92. Which of the following is the first computer to use Stored Program Concept? A) UNIVAC B) ENIAC C) EDSAC D) None of above
93. The term gigabyte refers to A) 1024 bytes B) 1024 kilobytes C) 1024 megabytes D) 1024 gigabyte
94. In which year was UK’s premier computing event called ?The which computer? started? A) 1980 B) 1985 C) 1986 D) 1987
95. Once you load the suitable program and provide required data, computer does not need human intervention. This feature is known as A) Accuracy B) Reliability C) Versatility D) Automatic
96. What is a brand? A) The name of companies that made computers B) The name of product a company gives to identify its product in market C) A name of class to indicate all similar products from different companies D) All of above
97. Machine language is A) Machine dependent B) Difficult to program C) Error prone D) All of above
98. A byte consists of A) One bit B) Four bits C) Eight bits D) Sixteen bits
99. Modern Computers are very reliable but they are not A) Fast B) Powerful C) Infallible D) Cheap
100. What is the date when Babbage conceived Analytical engine A) 1642 B) 1837 C) 1880 D) 1850
1-A 2-D 3-D 4-D 5-C 6-A 7-C 8-D 9-C 10-B 11-C 12-C 13-D 14-C 15-C 16-B 17-B 18-B 19-C 20-D 21-B 22-D 23-C 24-B 25-A 26-B 27-B 28-A 29-B 30-D 31-B 32-D 33-B 34-A 35-A 36-D 37-A 38-C 39-B 40-B 41-C 42-B 43-C 44-D 45-C 46-A 47-B 48-D 49-A 50-B 51-D 52-B 53-B 54-D 55-C 56-C 57-C 58-C 59-B 60-B 61-C 62-B 63-D 64-A 65-D 66-D 67-C 68-A 69-B 70-C 71-C 72-B 73-C 74-D 75-B 76-A 77-D 78-C 79-A 80-A 81-C 82-D 83-C 84-B 85-D 86-D 87-A 88-C 89-D 90-D 91-D 92-C 93-C 94-A 95-D 96-B 97-D 98-C 99-C 100-B COMPUTER NETWORKS 1. If a datagram router goes down then ………….. (A) All packets will suffer (B) Only those packets which are queued in the router at that time will suffer (C) Only those packets which are not queued in the router at that time will suffer (D) No packets will suffer Answer: B
2. In datagram subnet new route is chosen ………………… (A) For every packet sent (B) For all the packet sent (C) Only for the first packet (D) For the packet which is not transmitted Answer: A
3. The PSTN is an example of a ………………… network. (A) Packet switched (B) circuit switched (C) Message switched (D) None of these Answer: B
4. Each packet is routed independently in ………………. (A) Virtual circuit subnet (B) short circuit subnet (C) Datagram subnet (D) ATM subnet Answer: C
5. For a connection oriented service, we need a …………… (A) Virtual circuit subnet (B) short circuit subnet (C) Datagram subnet (D) wireless subnet Answer: C
6. Which type of switching uses the entire capacity of a dedicated link? (A) Circuit switching (B) Datagram packet switching (C) Virtual circuit packet switching (D) Message switching Answer: D
7. In …………… circuit switching, delivery of data is delayed because data must be stored and retrieved from RAM. (A) Space division (B) time division (C) Virtual (D) None of these Answer: B
8. In ……………., each packet of a message need not follow the same path from sender to receiver. (A) Circuit switching (B) Message switching (C) Virtual approach to packet switching (D) Datagram approach to packet switching Answer: D
9. In ………………, each packet of a message follows the same path from sender to receiver. (A) Circuit switching (B) Message switching (C) Virtual approach to packet switching (D) Datagram approach to packet switching Answer: A
10. A permanent virtual circuit involves …………….. (A) Connection establishment (B) Data transfer (C) Connection release (D) Connection check Answer: B
1. The set of optimal routes from all sources to a given destination from a tree rooted to the destination is known as …………….. (A) Binary tree (B) Sparse tree (C) Sink tree (D) AVL tree Answer: C
2. Adaptive routing algorithms get their information from …………. (A) Only from local environment (B) Only from adjacent routers (C) From locally, adjacent, external routers (D) Only from external routers Answer: C
3. If the route from I to J is computed in advance, off line, and downloaded to the routers when the network is booted is called as ………………. (A) Dynamic routing (B) Session routing (C) Temporary routing (D) Static routing Answer: D
4. In Hierarchical routing for N router subnet, the optimal number of levels is ………….. (A) logN (B) log(N -1) (C) lnN (D) ln(N-1) Answer: C
5. The router algorithm takes the decision to changes the route when …………….. (A) Router changes (B) Topology changes (C) User changes (D) Transmission time does not change Answer: B
6. If route from router I to router J is computed on line based on the current statistics, then it is called as ……………….. (A) Dynamic routing (B) Session routing (C) Temporary routing (D) None of these Answer: A
7. If the subnet uses virtual circuits internally, routing decisions are made only when a new virtual circuit is being setup. This is called as…………….. (A) Session routing (B) Circuit routing (C) Datagram routing (D) Forwarding Answer: A
8. …………….. change their routing decisions to reflect changes in the topology. (A) Non adaptive algorithms (B) Adaptive algorithms (C) Static algorithms (D) Recursive algorithms Answer: B
9. If router J is on the optimal path from router I to router K, then the path from J to K along the same route is ……………… (A) Does not exist (B) optimal (C) Maximum (D) constant Answer: B
10. If router J is on the optimal path from router I to router K, then the optimal path from J to K also falls along the same route is known as ……………….. (A) Routing principle (B) Optimality principle (C) Sink tree principle (D) Network principle Answer: B
1. ……………. do not base their routing decisions on measurements or estimates of the current traffic and topology. (A) Non adaptive algorithms (B) Adaptive algorithms (C) Static algorithms (D) Recursive algorithms Answer: A
2. The method of network routing where every possible path between transmitting and receiving DTE is used is called …………… (A) Random Routing (B) Packet Flooding (C) Directory Routing (D) Message Switching Answer: B
3. In Hierarchical routing, the routers are divided into what is called as …………….. (A) Zones (B) Cells (C) Regions (D) None of these Answer: C
4. The regions in Hierarchical routing are grouped in to …………….. (A) Clusters (B) Zones (C) Blocks (D) Cells Answer: A
5. The Clusters in Hierarchical routing are grouped in to ……………… (A) Clusters (B) Zones (C) Blocks (D) Cells Answer: B
6. If a router sends every incoming packet out only on those lines that are going approximately in the right direction is known as …………….. (A) Random flooding (B) Static flooding (C) Selective flooding (D) Early flooding Answer: C
7. In shortest path routing algorithm, the path length is measured based on …………….. (A) Time delay (B) number of hops (C) Size of the routers (D) routing table Answer: B
8. Flooding always choose the ……………….. (A) Shortest path (B) First path (C) Last path (D) Largest path Answer: A
9. In military applications where large number of routers may be blown to bits at any instant, we use ………………. (A) Shortest path first (B) First come first serve (C) Forwarding (D) Flooding Answer: D
10. In distributed applications, it is sometimes necessary to update all the databases concurrently, we use ………………….. (A) Shortest path first (B) First come first serve (C) Forwarding (D) Flooding
Answer: D 1. In multicast routing with spanning tree method, a network with n groups, each with an average of m members, for each group we require ……………….. (A) n pruned spanning trees must be stored for a total of mn trees (B) m pruned spanning trees must be stored for a total of m trees (C) n pruned spanning trees must be stored for a total of n trees (D) m pruned spanning trees must be stored for a total of mn trees Answer: D
2. To do multicast routing, each router computes a ………………… (A) Binary tree (B) AVL tree (C) Spanning tree (D) None of these Answer: C
3. A well -defined groups that are numerically large in size but small compared to the network as a whole are used in ………………….. (A) Unicast routing (B) Multicast routing (C) Broadcast routing (D) Telecast routing Answer: B
4. The processes that keep track of hosts whose home is in the area, but who currently visiting another area is …………….. (A) Home agent (B) Mobile agent (C) Foreign agent (D) User agent Answer: A
5. In ………………. to send a multicast message a host sends it to the core, which then does the multicast along the spanning tree. (A) Core based Trees (B) AVL trees (C) Binary trees (D) Sparse trees Answer: A
6. Sending a packet to all destinations simultaneously is called ………………. (A) Multicasting (B) Unicasting (C) Telecasting (D) Broadcasting Answer: D
7. A normal Flooding technique is an example of ……………… (A) Multicasting (B) Unicasting (C) Telecasting (D) Broadcasting Answer: D
8. In Broadcast routing, if the router does not know anything all about spanning tree………………. method is preferred. (A) Reverse Path forwarding (B) Multi-destination (C) Flooding (D) spanning tree Answer: A
9. The method of broadcast routing in which each packet contains either a list of destinations or a bit map indicating the desired destinations is ………………. (A) Reverse Path forwarding (B) Spanning tree (C) Multi-destination (D) Flooding Answer: C
10. Sending a message to a well defined group that are numerically large in size but small compared to the network as a whole is called ………………. (A) Unicasting (B) Multicasting (C) Broadcasting (D) None of these Answer: B
COMPUTER NETWORKS Interview Questions and Answers :-1. In link state routing, after the construction of link state packets new routes are computed using ………………… (A) Bellman Ford algorithm (B) DES algorithm (C) Dijkstra’s algorithm (D) Leaky bucket algorithm Answer: C
2. Count-to-Infinity problem occurs in ………………… (A) Distance vector routing (B) short path first (C) Link state routing (D) hierarchical routing Answer: A
3. In distance vector routing algorithm, each router maintains a separate routing table with the following entries. (A) Preferred input line , estimated time (B) Preferred input line, estimated distance (C) Preferred output line, estimated time (D) Preferred output line, router Answer: C
4. Link state packets are built in ……………….. (A) Short path first (B) distance vector routing (C) Link state routing (D) hierarchical routing Answer: B
5. In which routing method do all the routers have a common database? (A) Distance Vector (B) Link Vector (C) Shortest path (D) Link State Answer: D
6. In distance vector routing algorithm, the routing tables are updated ………………… (A) By exchanging information with the neighbours (B) Automatically (C) Using the backup database (D) By the server Answer: A
7. Distance vector routing algorithm is implemented in Internet as …………………… (A) OSPF (B) RIP (C) ARP (D) APR Answer: B
8. Which of the following routing algorithm takes into account the current network load. (A) Broadcast (B) shortest path (C) Flooding (D) distance vector routing Answer: D
9. In distance vector routing the delay metric is ………………. (A) Number of hops (B) geographical distance (C) Number of neighbours (D) queue length Answer: D
10. In AODV routing algorithm for MANETs, the route is discovered at time (A) Only when the network is established (B) In middle of the transmission (C) When there is a need for route by the host (D) When there is no need for route by the host Answer: C
1. Military vehicles on a battlefield with no existing infrastructure will deploy …………… network. (A) MANET (B) Cell Network (C) LAN (D) Wi-Fi Answer: A
2. The network in which all the nodes are symmetric and there is no central control or hierarchy is …………….. (A) MANET (B) Client -Server Technology (C) Peer-to-Peer (D) None of these Answer: C
3. What is the type of network in which the topology change from time to time? (A) Wi-Fi (B) Cell Network (C) LAN (D) MANET Answer: D
4. The processes that keep track of all mobile hosts visiting the area is …………….. (A) Home agent (B) Mobile agent (C) Foreign agent (D) User agent Answer: C
5. The hosts which are basically stationary hosts who move from one fixed site to another from time to time but use the network only when they are physically connected to it are called ……………. (A) Migratory hosts (B) Stationary hosts (C) Mobile hosts (D) Random hosts Answer: A
6. The hosts who compute on the run and want to maintain their connections as they move around …………… (A) Migratory hosts (B) Stationary hosts (C) Mobile hosts (D) Random hosts Answer: C
7. What is the type of network in which the routers themselves are mobile? (A) Wide Area Network (B) Mobile Ad hoc Network (C) Mobile Network (D) Local Area Network Answer: B
8. What is the routing algorithm used in MANETs? (A) Shortest Path First (B) Routing Information Protocol (C) Distance Vector Protocol (D) Ad hoc On -demand Distance Vector Protocol Answer: D
9. Why probe packets are transmitted in the network? (A) To know about the capacity of the channel (B) To count the number of host in the network (C) To know about efficiency of the routing algorithm (D) To know about the congestion Answer: D
10. If the source deduces the existence of congestion by making local observations, such as the time needed for acknowledgements to come back is called as …………….. (A) Explicit feedback algorithm (B) Implicit feedback algorithm (C) Explicit forward algorithm (D) Implicit forward algorithm Answer: B
1. Packet discard policy is implemented in …………….. (A) Physical layer (B) Data link layer (C) MAC layer (D) Network layer Answer: D
2. The solution to decrease the load on the network when congestion occurs is …………….. (A) Splitting the traffic over multiple routes (B) Increasing the transmission power (C) Usage of spare routers (D) Denying service to the users Answer: D
3. While booting the system the IP address is ……………. (A) 1.1.1.1 (B) 1.1.0.0 (C) 0.0.1.1 (D) 0.0.0.0 Answer: D
4. In open loop congestion control techniques, the decisions are based on the …………… (A) Without regard to the current state of the network (B) With regard to the current state of the network (C) With regard to the choice of the host (D) Without regard to the choice of the host Answer: A
5. In closed loop congestion control techniques, the decisions are based on the …………….. (A) concept of a feedback loop (B) Concept of a forward loop (C) Concept of current state of network (D) None of these Answer: A
6. ..………..is used to validate the identity of the message sender to the recipient (A) Encryption (B) Decryption (C) Digital certificate (D) None of these Answer: C
7. When too many packets are present in the subnet, and performance degrades then it leads to ……………….. (A) Ingestion (B) Congestion (C) Digestion (D) Diffusion Answer: B
8. What is it goal of congestion control? (A) Making sure that subnet is not able to carry the offered traffic (B) Making sure that subnet will allow more than the offered packets (C) Making sure that subnet is able to carry the offered traffic (D) Making sure that subnet will not allow any traffic Answer: C
9. The service of open loop congestion control technique is ………………….. (A) Monitor the system to detect when and where congestion occurs (B) When to accept new traffic (C) Pass the information to places where action can be taken (D) Adjusting the system to correct the problem Answer: B
10. In …………… case higher bandwidth can be achieved. (A) Connectionless networks (B) connection oriented networks (C) Virtual circuit networks (D) optical networks Answer: A
1. Time out determination policy is used in ………………….. (A) Network layer (B) data link layer (C) Transport layer (D) application layer Answer: C
2. In transport layer, End to End delivery is the movement of data from ………………. (A) One station to the next station (B) One network to the other network (C) Source to destination (D) One router to another router Answer: C
3. The service of closed loop congestion control technique is ……………… (A) When to accept new traffic (B) When to discard the packets (C) Monitor the system to detect when and where congestion occurs (D) Which packets to discard Answer: C
4. The solution to increase the capacity when congestion occurs is ………………… (A) Denying service to the users (B) Degrading the service to the users (C) Splitting traffic over multiple routes (D) Rescheduled the demands of the users Answer: C
5. When routers are being inundated by packets that they cannot handle, they just throw them away is known as ………………. (A) Jitter control (B) Random early detection (C) Choke packets (D) Load shedding Answer: D
6. Upon receipt of a bad segment, UDP ………….. (A) It does flow control (B) It does error control (C) Retransmission (D) It does not do flow and error control Answer: D
7. When the source host receives the choke packet, then the source ……………… (A) Reduces the capacity of the line (B) Reduces the line utilization factor (C) Reduces the traffic generation (D) Rate reduces the threshold value Answer: C
8. If the buffer fills and a packet segment is dropped, then dropping all the rest of the segments from that packet, since they will be useless anyway is called ……………….. (A) Priority dropping (B) Tail dropping (C) Age based dropping (D) None of these Answer: B
9. Flow control policy is implemented in …………………. (A) Network layer (B) transport layer (C) Application layer (D) physical layer Answer: B
10. For applications such as audio and video streaming, the variation in the packet arrival times is called …………….. (A) Random early detection (B) Jitter (C) Delay difference (D) Load shedding Answer: B
1. Which of the following is required to communicate between two computers? (A) Communications software (B) Protocol (C) Communication hardware (D) all of above including access to transmission medium Answer: D
2. Terminals are required for …………….. (A) real-time, batch processing & time-sharing (B) Real time, time-sharing & distributed message processing (C) Real time, distributed processing & manager inquiry (D) Real-time, time sharing & message switching Answer: D
3. The first collision free protocol is ………………. (A) Binary countdown (B) Basic bitmap (C) Reservation protocol (D) SAP Answer: B
4. Sending of a IP packet from host 1 to host 2 where both are of same LAN but the packet is transferred through different intermediate LANs is called ……………… (A) Tunneling (B) Routing (C) Diverting (D) Forwarding Answer: A
5. LANs can be connected by a device called …………….. (A) Routers (B) Modems (C) Ethernet card (D) Bridges Answer: D
6. In ……………….. all frames are given to the computer, not to those addressed. (A) Promiscuous mode (B) Miscues mode (C) Normal mode (D) Special Mode Answer: A
7. ……………… Algorithm is used in transparent bridges. (A) Forward Learning (B) Backward Learning (C) Reverse Backward Learning (D) Reverse Forward Learning Answer: B
8. In ………………… each packet of a message need not follow the same path From sender to receiver. (A) Circuit switching (B) Message switching (C) A virtual approach to packet switching (D) The datagram approach to packet switching Answer: D
9. FDDI is an acronym for …………… (A) Fast data delivery interface (B) Fiber distributed data interface (C) Fiber distributed digital interface (D) fast distributed data interface Answer: B
10. ……………….. bridge operates in promiscuous mode. (A) Transparent bridge (B) Selective flooding (C) Source Routing (D) Remote Bridges Answer: A
11. The address field of a frame in HDLC protocol contains the address of the ……………… station. (A) Primary (B) secondary (C) Tertiary (D) a station Answer: B
12. In ………………. transmission, the channel capacity is shared by both communicating devices at all times. (A) Simplex (B) half-duplex (C) full-duplex (D) automatic Answer: C
13. The DNS name space is divided into non overlapping …………………. (A) Regions (B) blocks (C) Divisions (D) zones Answer: D
14. Source routing bridges in the same LANs must have …………… bridge Number. (A) Same (B) Different (C) Source (D) Destination Answer: B
15. Repeater function in the …………………. layer. (A) Physical (B) Data link (C) Network (D) None of these Answer: A
16. A repeater takes a weakened or corrupted signal and …………… it. (A) Amplifies (B) Regenerates (C) Resample (D) Reroute Answer: B
17. The PSTN is an example of …………….. network. (A) packet-switched (B) circuit-switched (C) message-switched (D) TSI Answer: B
18. In a time division switch, a ……………… governs the destination of a packet stored in RAM. (A) TDM bus (B) cross bar (C) Cross point (D) control unit Answer: D
19. How many cross points are needed in a single stage switch with 40 inputs and 50 outputs. (A) 40 (B) 50 (C) 90 (D) 2000 Answer: D
20. The …………….. of A TSI controls the order of delivering of slot values that are stored in RAM. (A) Cross bar (B) cross point (C) Control unit (D) transceiver Answer: D ELECTRONICS & INSTRUMENTATION Part-1 1. Self generating type transducers are ______transducers. a) Active b) Passive c) Secondary d) Inverse Ans : (a)
2. The transducers that convert the input signal into the output signal, which is a discrete function of time is known as ______transducer. a) Active b) Analog c) Digital d) Pulse Ans : (c)
3. A transducer that converts measured into the form of pulse is called a) Active transducer b) Analog transducer c) Digital transducer d) Pulse transducer Ans : (d)
4. Which of the following is a digital transducer? a) Strain gauge b) Encoder c) Thermistor d) LVDT Ans : (b)
5. Strain gauge, LVDT and thermocouple are examples of a) Active transducers b) Passive transducers c) Analog transducers d) Primary transducers Ans : (c)
6. An inverse transducer is a device which converts a) An electrical quantity into a non electrical quantity b) Electrical quantity into mechanical quantity c) Electrical energy into thermal energy d) Electrical energy into light energy Ans : (a)
7. A strain gauge is a passive transducer and is employed for converting a) Mechanical displacement into a change of resistance b) Pressure into a change of resistance c) Force into a displacement d) Pressure into displacement Ans : (a)
8. Resolution of a transducer depends on a) Material of wire b) Length of wire c) Diameter of wire d) Excitation voltage Ans : (c)
9. The sensitivity factor of strain gauge is normally of the order of a) 1 to 1.5 b) 1.5 to 2.0 c) 0.5 to 1.0 d) 5 to 10 Ans : (b)
10. In wire wound strain gauges, the change in resistance is due to a) Change in diameter of the wire b) Change in length of the wire c) Change in both length and diameter d) Change in resistivity Ans : (c)
11. Bonded wire strain gauges are a) Exclusively used for construction of transducers b) Exclusively used for stress analysis c) Used for both stress analysis and construction of transducer d) Pressure measurement Ans : (c)
12. Certain type of materials generates an electrostatic charge or voltage when mechanical force is applied across them. Such materials are called a) Piezo-electric b) Photo-electric c) Thermo-electric d) Photo-resistive Ans : (a)
13. Quartz and Rochelle salt belongs to ______of piezo-electric materials a) Natural group b) Synthetic group c) Natural or Synthetic group d) Fiber group Ans : (a)
14. Which of the following are piezo electric substances? 1. Barium titanate 2. Lead titanate 3. Lead Zirconate 4. Cadmium and sulphate a) 1,2 and 4 b) 1,3and4 c) 1,2and 3 d) 2,3and 4 Ans : (c)
15. Piezo-electric transducers are a) Passive transducers b) Inverse transducers c) Digital transducers d) Pulse transducers Ans : (b)
16. Piezo – electric transducers work when we apply ______to it. a) Mechanical force b) Vibrations c) Illuminations d) Heat Ans : (d)
17. Piezo electric crystal can produce an emf a) When external mechanical force is applied to i b) When radiant energy stimulates the crystal c) When external magnetic field is applied d) When the junction of two such crystals are heated Ans : (a)
18. The draw backs of strain gauges are S1: Low fatigue life S2: They are expensive, brittle and sensitive to temperature S3: Poor linearity a) S1 and S2 b) S2 and S3 c) S1 and S3 d) S1 only Ans : (b)
19. LVDT windings are wound on a) Steel sheets b) Aluminium c) Ferrite d) Copper Ans : (c)
20. The size of air cored transducers in comparison to the iron core parts is a) Smaller b) Larger c) Same d) Unpredictable Ans : (b)
21. The principle of operation of LVDT is based on the variation of a) Self inductance b) Mutual inductance c) Reluctance d) Permanence Ans : (b)
22. LVDT is an/a ______transducer a) Magneto-strict ion b) Inductive c) Resistive d) Eddy current Ans : (d)
23. Which of the following can be measured with the help of piezo electric crystal? a) Force b) Velocity c) Sound d) Pressure Ans : (a)
24. S1: Transducer is a device which converts physical into electrical quantity S2: Transducer is also called as sensor. a) S1 is true & S2 is false b) S2 is true & S1 is false c) Both S1 & S2 are true d) Both S1 & S2 are false Ans (b)
27. In a LVDT, the two secondary voltages a) Are independent of the core position b) Vary unequally depending on the core position c) Vary equally depending on the core position d) Are always in phase quadrature Ans : (b)
28. Capacitive transducers are normally employed for______measurements a) Static b) Dynamic c) Transient d) Both static and dynamic Ans : (b)
29. Match the following 1. EEG A. Diagnostic tool for heart alignment 2. ECG B. Diagnostic tool for brain alignment 3. Sphygmo-manometer C. Instrument used for measuring blood pressure 4. Stethoscope D. instrument used to hear pulse/heart beat a) 1- B, 2 – A, 3 – C, 4 – D b) 1 – B, 2 – A, 3 – D, 4 – C c) 1- C, 2 – A, 3 – B, 4 – D d) 1 – A, 2 – B, 3 – C, 4 – D Ans : (a)
30. Pick the correct statement regarding functions of a transducer S1: Sense the magnitude, change in & / or frequency of same measurand S2: To provide electrical output that furnishes accurate, quantitative data about the measurand a) S1 is true & S2 is false b) S2 is true & S1 is false c) Both S1 & S2 are true d) Both S1 & S2 are false Ans : (c)
31. The transducers which requires an external power and their output is a measure of some variation such as resistance, inductance, capacitance etc., are called as a) Active transducer b) Primary sensor c) Passive transducer d) Self generating transducer Ans : (c)
32. The principle of operation of variable resistance transducer is a) Deformation leads to change in resistance b) Displacement of a contact slider on a resistance c) Coupling of two coils changes with displacement d) Movement of magnetic field produces variation in resistance of material Ans : (b)
33. The application of LVDT is a) Joint motion b) Finger movement c) Limb movement d) Heart wall motion Ans : (c)
34. Venturi is associated with a) Venous blood pressure b) Digital plethysmography c) Dialysate flow in artificial kidney d) Blood flow in heart lung machine Ans : (d)
35. Pressure transducer for measuring blood pressure is a) Strain gauge transducer only b) Strain gauge or capacitive transducer c) Resistive transducer d) Fiber optic transducer Ans : (b)
36. The change in resistance of a metal wire owing to strain is due to S1: Change in dimension of wire expressed by factor (1-2µ) S2: Change in resistance ?? a) S1 is true & S2 is false b) S2 is true & S1 is false c) Both S1 & S2 are true d) Both S1 & S2 are false Ans : (b)
37. In foil strain gauge the thickness of foil varies from a) 2.5 micron to 6 micron b) 25 micron (or) less c) 25 micron to 60 micron d) 2.5 micron to 5 micron Ans : (a)
38. Photo conductive cell consists of a thin film of a) Quartz b) Lithium sulphate c) Barium titanate d) Selenium Ans : (d)
39. S1: In multimode fiber optics, intensity modulating schemes can be employed. S2: Schemes using polarizing techniques need birefringent fiber. a) S1 is true and S2 is false b) Both S1 and S2 are true c) S1 is false and S2 is true d) Both S1 and S2 are false ans (b)
40. Test electrode is also known as a) Indicator electrode b) Reference electrode c) Second electrode d) Primary electrode Ans : (a)
41. Most commonly used indicator electrode is a) Calomel electrode b) Silver electrode c) Silver – Silver chloride electrode d) Glass electrode Ans : (d)
42. ______is the example of photo emissive cell a) LDR b) Photo diode c) Photo transistor d) Photo multiplier Ans : (a)
43. pH value of venous blood is a) 7.30 b) 7.40 c) 7.35 d) 7.45 Ans : (c)
44. Silver chloride electrode is used as a reference electrode due to its a) Large half cell potential b) Stable half cell potential c) Stable resting potential d) Stable action potential Ans : (b)
45. The capacitance microphone is used for the detection of a) Heart rate b) Blood flow c) Heart sound d) Foot pressure Ans : (c)
46. In a graded index fiber, the total reflected light takes a ______a) Straight line path b) Parabolic path c) Elliptical path d) Circular path Ans (b)
47. ______fiber is used in interferometric instruments. a) Monomode b) Multimode c) Birefringent d) Coated Ans (a)
48. Fiber optic sensor can be used to sense ______a) Displacement b) Power c) Current d) Resistance Ans (a)
49. Photo multiplier consists of a) 1 Photo emissive cathode & 2 dynodes b) 2 Photo emissive cathodes & 2 dynodes c) 2 Photo emissive cathodes & 1 dynode d) 1 Photo emissive cathode & 1 dynode Ans : (a)
50. The resistance of LDR ______when exposed to radiant energy. a) Remains unaltered b) Increases c) Reaches maximum d) Decreases Ans : (d)
Part-2 1. The decibel is a measure of a) Current b) Voltage c) Power d) Power level Ans : (d)
2. Power gain in decibels is equal to voltage gain in decibels only when a) Input impedance is equal to output impedance b) Output impedance is zero c) Never d) Input impedance is zero Ans : (a)
3. An ideal amplifier has a) Noise figure of 0 db b) Noise figure of more than 0 db c) Noise factor of unity d) Noise figure of less than 1 db Ans : (c)
4. Fidelity represents S1: Reproduction of signal S2: Reproduction of phase relation a) S1 and S2 are true b) S1 and S2 are false c) S1 false and S2 true d) S1 true and S2 false Ans : (d)
5. If the current gain of the amplifier is X, its voltage gain is Y, then its power gain will be a) X/Y b) X*Y c) X+Y d) X-Y Ans : (b)
6. In an amplifier, the coupling capacitors are employed for a) Limiting the bandwidth b) Matching the impedance c) Preventing of Dc mixing with input or output d) Controlling the output Ans : (c)
7. The amplifier which has no drift is called as a) Differential amplifier b) DC amplifier c) Single ended amplifier d) Chopper amplifier Ans : (d)
8. The amplifier gain varies with frequency. This happens mainly due to a) Miller effect b) Presence of external and internal capacitance c) Logarithmic increase in its output d) Inter stage transformer Ans : (b)
9. The outstanding characteristics of a D.C. amplifier is its a) Ability to amplify Dc and low frequency signals b) Temperature stability c) Utmost economy d) Avoidance of frequency sensitive components Ans : (a)
10. Isolation amplifier actually operates on the principle of a) Filtering b) Attenuation c) Clipping d) Amplification Ans : (b)
11. Isolation amplifiers are also called as a) DC amplifier b) Output amplifier c) Inverting amplifier d) Iso-amps Ans : (d)
12. The improper response time of the amplifier in the biomedical recorders a) Affects the gain of the amplifier b) Delays the signals c) Changes the shape of the waveform of the signal d) Attenuates the signals Ans : (c)
13. To reduce common mode interference during recording of bio signals one can use______a) Buffer amplifier b) Differential amplifier c) Single ended amplifier d) Chopper amplifier Ans : (b)
14. Resistively generated inference arises through incorrect ______a) Grounding b) Current density at the electrodes c) Supply voltage d) Input impedance Ans : (a)
15. CMRR is more in______a) Single ended amplifier b) Differential amplifier c) Inverting operational amplifier d) Chopper amplifier Ans : (b)
16. For biomedical applications the mostly used amplifier is a) Single ended amplifier b) Differential amplifier c) Inverting operational amplifier d) Chopper amplifier Ans : (b)
17. ______amplifier is used to drive the recorder. a) Power amplifier b) Pre amplifier c) Operational amplifier d) Differential amplifier Ans : (a)
18. When a number of components are fabricated on same IC chip it is necessary to provide isolation between two different components for input interconnection is called ______a) Input amplification b) Input differentiation c) Common mode rejection d) Input isolation Ans : (d)
19. A chopper amplifier a) Converts AC signal from low frequency to high frequency b) Converts DC signal from low frequency to high frequency c) Converts AC signal from low frequency to DC high frequency d) Converts DC signal from low frequency to high frequency Ans : (b)
20. Power amplifier is provided with S1: Cross over distortion compensation S2: Offset control a) S1 is true & S2 is false b) S2 is true & S1 is false c) Both S1 & S2 are true d) Both S1 & S2 are false Ans : (c)
21. Pre amplifier isolation in ECG circuit is to a) Increase input impedance b) Decrease input impedance c) Increase output impedance d) Decrease output impedance Ans : (a)
22. Raising input impedance of pre amplifier reduces a) Input current b) Output current c) Stray current d) Grid current Ans : (c)
23. Common mode rejection ratio is defined as ratio of a) Common mode gain to differential mode gain b) Differential mode gain to common mode gain c) Common mode gain at input to differential mode gain at input d) Common mode gain at output to differential mode gain at output Ans : (b)
24. An electrometer amplifier has high input impedance of a) 1010? b) 105? c) 1020? d) 1015? Ans : (d)
25. When the input of differential amplifier V1 = 0, then the differential amplifier is said to be operated in a) Common mode b) Differential mode c) Non inverting mode d) Inverting mode Ans : (c)
26. When either one of the inputs to the differential amplifier is equal to zero then it is said to be operated in a) Single ended mode b) Differential mode c) Non inverting mode d) Inverting mode Ans : (a)
27. The negative feedback in an amplifier a) Reduces voltage gain b) Increases the voltage gain c) Increases the gain band width product d) Reduces the input impedances Ans : (a)
28. Feedback in an amplifier always helps in a) Increasing its input impedance b) Increasing its gain c) Controlling its output d) Stabilizes its gain Ans : (c)
29. Using mechanical chopper we cannot achieve high chopping rates due to their a) Input impedance b) Output impedance c) Response time d) Inertia Ans : (d)
30. The CMRR of a typical IC OPAMP is a) 70 dB b) 80 dB c) 85 dB d) 75 dB Ans : (b)
31. A ______is usually a display device used to produce a paper record of analog wave form. a) Graphic pen recorder b) Electron microscope c) X-Y recorder d) Oscilloscope Ans : (a)
32. The ______of a recording system is the magnitude of input voltage required to produce a standard deflection in a recorded trace. a) Accuracy b) Linearity c) Sensitivity d) Resolution Ans : (c)
33. A recorder is said to have good frequency response when the sensitivity of the system is ______for all frequencies present in the signal. a) Unity b) Zero c) Infinity d) Constant Ans : (d)
34. In phase response of a recorder noise level ______with the band width of a system a) Increases b) Decreases c) Reaches unity d) Reaches infinity Ans : (a)
35. Function of microscope is S1: To magnify object, under observation S2: To resolve the object a) S1 is true & S2 is false b) S2 is true & S1 is false c) Both S1 & S2 are true d) Both S1 & S2 are false Ans : (c)
36. In electron microscope the projection of the motion on a plane normal to magnetic induction (B) will be a circle of radius (r) = a) mVsin?+eB b) mVsin?/eB c) mVsin?-eB d) mVsin?*eB Ans : (b)
37. Match the following 1. Electron microscope – (A) Electron gun 2. Oscilloscope – (B) Condensing magnetic lens 3. Galvanometric recorder – (C) Recording head 4. Magnetic recorder – (D) Drive motor a) 1-A, 2-B, 3-C, 4-D b) 1-D, 2-C, 3-B, 4-A c) 1-B, 2-A, 3-D, 4-C d) 1-C, 2-D, 3-A, 4-B Ans : (c)
38. In PMMC writing system, the magnitude of pen deflection is proportional to S1: Current flowing through the coil S2: Voltage in the coil a) S1 is true & S2 is false b) S2 is true & S1 is false c) Both S1 & S2 are true d) Both S1 & S2 are false Ans : (a)
39. Duration of rotation of pen in the PMMC system depends upon ______a) Phase angle b) Frequency c) Magnitude d) Direction Ans : (d)
40. The shorter wave length of the electron permits the detailed examination of tiny objects due to reduction of ______effects a) Reflection b) Diffraction c) Refraction d) Polarization Ans : (b)
41. Which of the following recorder gives slow response a) X-Y recorder b) Oscillographic c) Galvanometric d) Magnetic Ans : (c)
42. The use of storage oscilloscope S1: Viewing rapidly changing non repetitive wave forms S2: Recording average values a) S1 is true & S2 is false b) S2 is true & S1 is false c) Both S1 & S2 are true d) Both S1 & S2 are false Ans : (b)
43. In X-Y recorders, the self balancing potentiometers plot emf as a function of a) Another emf b) Frequency c) Time d) Pressure Ans : (a)
44. In strip chart recorders, the self balancing potentiometers plot emf as a function of a) Another emf b) Frequency c) Time d) Pressure Ans : (c)
45. The slewing speed of X-Y recorder is a) 1.6 m/s b) 1.3 m/s c) 1.4 m/s d) 1.5 m/s Ans : (d)
46. The resolution limit of electron microscope is a) 2 A.V b) 1 A.V c) 1.5 A.V d) 1.2 A.V Ans : (b)
47. ______is also known as halftone storage or mersh storage. a) Variable persistence storage b) Bistable storage c) Flat storage d) CRT Ans : (a)
48. Storage oscilloscope operates on the principle of a) Primary emission b) Deflection c) Secondary emission d) Diffusion Ans : (c)
49. The writing speed of fast storage oscilloscope is a) 2000 cm/?s b) 1000 cm/?s c) 1500 cm/?s d) 2500 cm/?s Ans : (a)
50. Stress and strain curves are plotted using a) Magnetic tape recording b) X-Y recording c) Galvanometric d) PMMC writing systems Ans : (b) C++ Programming 1. If the class name is X, what is the type of its “this” pointer (in a nonstatic, non-const member function)? a. const X* const b. X* const c. X* d. X&
2. Which classes allow primitive types to be accessed as objects? a. Storage b. Virtual c. Friend d. Wrapper
3. When is std::bad_alloc exception thrown? a. When new operator cannot allocate memory b. When alloc function fails c. When type requested for new operation is considered bad, thisexception is thrown d. When delete operator cannot delete the allocated (corrupted) object
4. Which one of the following is not a fundamental data type in C++ a. float b. string c. int d. wchar_t
5. Which of the following is a valid destructor of the class name “Country” a. int ~Country() b. void Country() c. int ~Country(Country obj) d. void ~Country()
6. Which of the following correctly describes C++ language? a. Statically typed language b. Dynamically typed language c. Both Statically and dynamically typed language d. Type-less language
7. Which of the following keyword supports dynamic method resolution? a. abstract b. Virtual c. Dynamic d. Typeid
8. Which of the following is the most preferred way of throwing and handling exceptions? a. Throw by value and catch by reference. b. Throw by reference and catch by reference. c. Throw by value and catch by value d. Throw the pointer value and provide catch for the pointer type.
9. Which of the following is not true about preprocessor directives a. They begin with a hash symbol b. They are processed by a preprocessor c. They form an integral part of the code d. They have to end with a semi colon
10. What’s wrong? while( (i < 10) && (i > 24)) a. the logical operator && cannot be used in a test condition b. the while loop is an exit-condition loop c. the test condition is always false d. the test condition is always true
11. A continue statement causes execution to skip to a. the return 0; statement b. the first statement after the loop c. the statement following the continue statement d. the next iteration of the loop
12. What’s wrong? (x = 4 && y = 5) ? (a = 5) ; (b = 6); a. the question mark should be an equal sign b. the first semicolon should be a colon c. there are too many variables in the statement d. the conditional operator is only used with apstrings
13. What’s wrong? for (int k = 2, k <=12, k++) a. the increment should always be ++k b. the variable must always be the letter i when using a for loop c. there should be a semicolon at the end of the statement d. the commas should be semicolons
14. Which of the following is not recommended in a header file? a. Type definitions (typedefs) b. Class definitions c. Function definitions d. Template definitions
15. Which of the STL containers store the elements contiguously (in adjacent memory locations)? a. std::vector b. std::list c. std::map d. std::set
16. Which of the following is not a standard exception built in C++. a. std::bad_creat b. std::bad_alloc c. std::bad_cast d. std::bad_typeid
17. What does STL stand for? a. Simple Template Library b. Standard Template Library c. Static Type Library d. Single Type-based Library
18. What is the difference between overloaded functions and overridden functions? a. Overloading is a dynamic or run-time binding and Overriding is static or compile-time binding b. Redefining a function in a friend class is called function overriding while Redefining a function in a derived class is called an overloaded function. c. Overloading is a static or compile-time binding and Overriding is dynamic or run-time binding d. Redefining a function in a friend class is called function overloading while Redefining a function in a derived class is called as overridden function.
19. Which one of the following is not a valid reserved keyword in C++ a. Explicit b. Public c. Implicit d. Private
20. Each pass through a loop is called a/an a. enumeration b. iteration c. culmination d. pass through
Correct Answers to C++ MCQ Questions 1 – d 2 – b 3 – d 4 – a 5 – b 6 – d 7 – a 8 – b 9 – a 10 – d 11 – c 12 – d 13 – b 14 – d 15 – c 16 – a 17 – b 18 – b 19 – c 20 – c
21. Which of the following is true about const member functions? a. const members can be invoked on both const as well as nonconst objects b. const members can be invoked only on const objects and not on nonconst objects c. nonconst members can be invoked on const objects as well as nonconst objects d. none of the above
22. Which of the following relationship is known as inheritancerelationship? a. ‘has-a’ relationship b. ‘is-a’ relationship c. association relationship d. none of the above
23. If class A is friend of class B and if class B is friend of class C, which of the following is true? a. Class C is friend of class A b. Class A is friend of class C c. Class A and Class C do not have any friend relationship d. None of the above
24. A direct access file is: a. A file in which recoreds are arranged in a way they are inserted in a file b. A file in which records are arranged in a particular order c. Files which are stored on a direct access storage medium d. None of the above
25. Which of the following is not a component of file system a. Access method b. Auxiliary storage management c. Free integrity mechanism d. None of the above
26. Seek time is a. time taken to retrieve a data b. Time taken by read/write head mechanism to position itself over appropriate cylinder c. Time taken by appropriate sector to come under read/write d. None of the above
27. ‘Prime area’ in context of file system is defined as a. It is memory area created by operating system b. It is an area into which data records are written c. It is the main area of a web page d. None of the above
28. In multi-list organization a. Records that have equivalent value for a given secondary index item are linked together to form a list. b. Records are loaded in ordered sequence defined by collating sequence by content of the key c. Records are directly accessed by record key field d. None of the above
29. Which of the following is/are advantages of cellular partitioned structure: a. Simultaneous read operations can be overlapped b. Search time is reduced c. Both a & b d. None of the above
30. *ptr++ is equivalenet to: a. ptr++ b. *ptr c. ++*ptr d. None of the above
31. The conditional compilation a. It is taken care of by the compiler b. It is setting the compiler option conditionally c. It is compiling a program based on a condition d. none of above
32. Originally ‘C’ was developed as: a. System programming language b. General purpose language c. Data processing language d. None of above
33. An inverted file a. Locates information about data in small files that are maintained apart from actual data record b. A file which stores opposite records c. A file which stores information about records of a system d. None of above
34. Which of the following is not a file operation: a. Repositioning b. Truncating c. Appending d. None of above
35. Latency time is: a. Time taken by read/write head mechanism to position itself over appropriate cylinder b. Time taken to transfer a dta from memory c. Time taken by appropriate sector to come under read/write head d. None of above
36. The two types of file structure existing in VSAM file are a. Key sequenced structure, entry sequenced structure b. Key sequence structure, exit sequenced structure c. Entry sequence structure, exit sequenced structure d. None of above
37. How many copies of a class static member are shared between objects of the class? a. A copy of the static member is shared by all objects of a class b. A copy is created only when at least one object is created from that class c. A copy of the static member is created for each instantiation of the class d. No memory is allocated for static members of a class
38. Which looping process checks the test condition at the end of the loop? a. for b. while c. do-while d. no looping process checks the test condition at the end
39. The default access level assigned to members of a class is ______a. Private b. Public c. Protected d. Needs to be assigned
40. Which of the following correctly describes the meaning of ‘namespace’ feature in C++? a. Namespaces refer to the memory space allocated for names used in a program b. Namespaces refer to space between the names in a program c. Namespaces refer to packing structure of classes in a program. d. Namespaces provide facilities for organizing the names in a program to avoid name clashes.
Correct Answers to C++ MCQ Questions 21 – b 22 – a 23 – b 24 – c 25 – c 26 – d 27 – b 28 – b 29 – a 30 – c 31 – d 32 – c 33 – b 34 – a 35 – d 36 – c 37 – c 38 – a 39 – c 40 – a
41. Which of the following correctly describes the meaning of ‘namespace’ feature in C++? a. Namespaces refer to the memory space allocated for names used in a program b. Namespaces refer to space between teh names in a program c. Namespaces refer to space between the names in a program d. namespaces provide facilities for organizing the names in a program to avoid name clashes
42. Which of the following language is not supported by C++? a. Exception Handling b. Reflection c. Operator Overloading d. Namespaces
43. class derived: public base1, public base2 { } is an example of a. Polymorphic inheritance b. Multilevel inheritance c. Hierarchical inheritance d. Multiple inheritance
44. Which of the following languages is a subset of C++ language? a. C language b. Java Language c. C# language d. language
45. How do we declare an ‘interface’ class? a. By making all the methods pure virtual in a class b. By making all the methods abstract using the keyword ‘abstract’ in a class c. By declaring the class as interface with the keyword ‘interface’ d. It is not possible to create interface class in C++
46. How do we declare an abstract class? a. By providing at least one pure virtual method (function signature followed by ==0;) in a class b. By declaring at least one method abstract using the keyword ‘abstract’ in a class c. By declaring the class abstract with the keyword ‘abstract’ d. It is not possible to create abstract classes in C++
47. Which of the following is not an advantage of secondary memory a. It is cost-effective b. It has large storage capacity c. It has highest speed d. It is easily portable
48. What happens when a pointer is deleted twice? a. It can abort the program b. It can cause a failure c. It can cause an error d. It can cause a trap
49. Which of the following language feature is not an access specifier in C++? a. public b. private c. C protected d. internal
50. Expression C=i++ causes a. Value of i assigned to C and then i incremented by 1 b. i to be incremented by 1 and then value of i assigned to C c. Value of i assigned to C d. i to be incremented by 1
51. The statement i++; is equivalent to a. i = i + i; b. i = i + 1; c. i = i – 1; d. i –;
52. In C language, a hexadecimal number is represented by writing a. x b. xo c. ox d. h
53. Which of the following library function below by default aborts the program? a. Terminate() b. end() c. Abort() d. exit()
54. If a member needs to have unique value for all the objects of that same class, declare the member as a. Global variable outside class b. Local variable inside constructor c. Static variable inside class d. Dynamic variable inside class
55. Value of ix+j, if i,j are integer type and ix long type would be a. integer b. float c. long integer d. double percision
56. Which of the following below can perform conversions between pointers to related classes? a. A. cast_static b. B. dynamic_cast c. c. static_cast d. D. cast_dynamic
57. How do we define a constructor? a. a. x~() {} b. B. X() {}~ c. C. X() ~{} d. D. ~X() {}
58. Vtables a. creates a static table per class b. creates a static table per object c. creates a dynamic table per class d. creates a dynamic table per object
59. When class B is inherited from class A, what is the order in which the constructers of those classes are called a. Class A first Class B next b. Class B first Class A next c. Class B’s only as it is the child class d. Class A’s only as it is the parent class
60. Which of the following is the most general exception handler that catches exception of any type? a. catch(std::exception) b. catch(std::any_exception) c. catch(…) d. catch()
Correct Answers to C++ MCQ Questions 41 – d 42 – d 43 – b 44 – d 45 – a 46 – a 47 – a 48 – c 49 – d 50 – d 51 – a 52 – b 53 – d 54 – a 55 – b 56 – c 57 – C 58 – D 59 – a 60 – a
61. Which of the following is the most general exception handler that catches exception of ‘any type’? a. catch(std::exception) b. catch(std::any_exception) c. catch(…) d. catch()
62. In a group of nested loops, which loop is executed the most number of times? a. the outermost loop b. the innermost loop c. all loops are executed the same number of times d. cannot be determined without knowing the size of the loops
63. What is the Difference between struct and class in terms of Access Modifier? a. By default all the struct members are private while by default class members are public. b. By default all the struct members are protected while by default class members are private. c. By default all the struct members are public while by default class members are private. d. By default all the struct members are public while by default class members are protected.
64. Inline functions are invoked at the time of a. Run time b. Compile time c. Depends on how it is invoked d. Both b and c above
65. What is shallow copy? a. A shallow copy creates a copy of the dynamically allocated objects too. b. A shallow copy just copies the values of the data as they are. c. A shallow copy creates a copy of the statically allocated objects too d. Both b and c above
66. What is deep copy? a. A deep copy creates a copy of the dynamically allocated objects too. b. A deep copy just copies the values of the data as they are. c. A deep copy creates a copy of the statically allocated objects too d. Both b and c above
67. Which of the following below is /are a valid iterator type? a. Input Iterator b. Backward Iterator c. Forward Iterator d. Both a and c above
68. What defines a general set of operations that will be applied to various types of data? a. Template class b. Function template c. Class template d. Both a and c above
69. Under which of the following circumstances, synchronization takes place? a. When the file is closed b. When the buffer is empty c. Explicitly, with manipulators d. both a and c
70. Which of the following functions below can be used Allocate space for array in memory? a. calloc() b. malloc() c. Realloc() d. both a and b
71. Statement scanf(“%d”,80); a. Assign an integer to variable i b. Give an error message c. Print the value of i d. Assign an float to variable i
72. STL is based on which of the following programming paradigms? a. Structured Programming b. Object Oriented Programming (OOP) c. Functional Programming d. Aspect Oriented Programming (AOP)
73. STL is based on which of the following programming paradigms? a. Structured Programming b. Object Oriented Programming (OOP) c. Functional Programming d. Aspect Oriented Programming (AOP)
74. If there is more than one statement in the block of a for loop, which of the following must be placed at the beginning and the ending of the loop block? a. parentheses ( ) b. braces { } c. brackets [ ]. d. arrows < >
75. Which of the following members do get inherited but become private members in child class a. Public b. Private c. Protected d. All the above
76. Which looping process is best used when the number of iterations is known? a. for b. while c. do-while d. all looping processes require that the iterations be known
77. In a C language ‘3’ represents a. A digit b. An integer c. A character d. A word
78. Which of the following is the most common way of implementing C++? a. C++ programs are directly compiled into native code by a compiler b. C++ programs are first compiled to intermediate code by a compiler and then executed by a virtual machine c. C++ programs are interpreted by an interpreter d. A C++ editor directly compiles and executes the program
79. Which header file should we include for using std::auto_ptr? a. b. c. d.
80. Which of the following operators can be implemented as a nonmember operator? #NAME? b. () (function call operator) c. [. (array access operator) d. + (addition operator)
Correct Answers to C++ MCQ Questions 61 – c 62 – c 63 – b 64 – c 65 – b 66 – b 67 – a 68 – d 69 – b 70 – d 71 – a 72 – a 73 – c 74 – c 75 – b 76 – c 77 – a 78 – c 79 – a 80 – c
81. What is the implicit pointer that is passed as the first argument for nonstatic member functions? a. ‘self’ pointer b. std::auto_ptr pointer c. ‘Myself’ pointer d. ‘this’ pointer
82. Which of the following operators can be overloaded? a. . (dot or member access operator) b. & (address-of operator) c. sizeof operator d. ?: (conditional operator)
83. Which of the following operator cannot be overloaded? #NAME? b. == (equality operator) c. –> (row operator) d. :: (cope resolution operator)
84. Which of the following operators below allow to define the member functions of a class outside the class? a. :: b. ? c. d. %
85. Which of the following is not a valid conditional inclusions in preprocessor directives a. #ifdef The linked image cannot be displayed. The file may have been moved, renamed, or deleted. Verify that the link points to the correct file and location. b. #ifundef c. #endif d. #elif
86. Which of the following is not a standard exception built in C++. a. std::bad_creat b. std::bad_alloc c. std::bad_cast d. std::bad_typeid
87. If a member needs to have unique value for all the objects of that same class, declare the member as a. Global variable outside class b. Local variable inside constructor c. Static variable inside class d. Dynamic variable inside class
88. Under which of the following circumstances, synchronization takes place? a. When the file is closed b. When the buffer is empty c. Explicitly, with manipulators d. both a and c
89. Which of the following functions below can be used Allocate space for array in memory? a. calloc() b. malloc() c. Realloc() d. both a and b
90. Which of the following is not a valid conditional inclusions in preprocessor directives a. #ifdef b. #ifundef c. #endif d. #elif
91. Value of a in a = (b = 5, b + 5); is a. Junk value b. Syntax error c. 5 d. 10
92. Minimum number of temporary variable needed to swap the contents of 2 variables is: a. 1 b. 2 c. 3 d. 0
94. There is nothing like a virtual constructor of a class. a. False b. True
95. C++ provides facility to specify that the compiler should match function calls with the correct definition at the run time. This process is called as a. Static binding b. Dynamic Binding
96. The output of this program is int main () { cout << “Hello World!” return 0; } a. Hello World b. Syntax error c. 0 d. Hello World!
97. The return value of the following code is Class1& test(Class1 obj) { Class1 *ptr = new Class1(); ……… return ptr; } a. object of Class1 b. reference to ptr c. reference of Class1 d. object pointed by ptr
98. The output of { int a = 5; int b = 10; cout << (a>b?a:b); } a. 5 b. 10 c. Syntax error d. None of above
99. The output of this program is int a = 10; void main() { int a = 20; cout << a << ::a; } a. Syntax error b. 10 20 c. 20 10 d. 20 20
100. Observe following program and answer class Example{ public: int a,b,c; Example(){a=b=c=1;} //Constructor 1 Example(int a){a = a; b = c = 1;} //Constructor 2 Example(int a,int b){a = a; b = b; c = 1;} //Constructor 3 Example(int a,int b,int c){ a = a; b = b; c = c;} //Constructor 4 } In the above example of constructor overloading, the following statement will call which constructor Example obj = new Example (1,2,3); a. Constructor 2 b. Constructor 4 c. Constrcutor 1 d. Type mismatch error
Correct Answers to C++ MCQ Questions 81 – d 82 – d 83 – b 84 – d 85 – a 86 – b 87 – a 88 – b 89 – d 90 – a 91 – b 92 – d 93 – d 94 – a 95 – b 96 – b 97 – b 98 – b 99 – c 100 – b DATA STRUCTURES and ALGORITHMS 1. Which if the following is/are the levels of implementation of data structure A) Abstract level B) Application level C) Implementation level D) All of the above
2. A binary search tree whose left subtree and right subtree differ in hight by at most 1 unit is called …… A) AVL tree B) Red-black tree C) Lemma tree D) None of the above
3. ……………….. level is where the model becomes compatible executable code A) Abstract level B) Application level C) Implementation level D) All of the above
4. Stack is also called as A) Last in first out B) First in last out C) Last in last out D) First in first out
5. Which of the following is true about the characteristics of abstract data types? i) It exports a type. ii) It exports a set of operations A) True, False B) False, True C) True, True D) False, False
6. …………… is not the component of data structure. A) Operations B) Storage Structures C) Algorithms D) None of above
7. Which of the following is not the part of ADT description? A) Data B) Operations C) Both of the above D) None of the above
8. Inserting an item into the stack when stack is not full is called …………. Operation and deletion of item form the stack, when stack is not empty is called ………..operation. A) Push, pop B) Pop, push C) Insert, delete D) Delete, insert
9. ……………. Is a pile in which items are added at one end and removed from the other. A) Stack B) Queue C) List D) None of the above
10. ………… is very useful in situation when data have to stored and then retrieved in reverse order. A) Stack B) Queue C) List D) Link list
11. Which data structure allows deleting data elements from and inserting at rear? A) Stacks B) Queues C) Dequeues D) Binary search tree
12. Which of the following data structure can’t store the non-homogeneous data elements? A) Arrays B) Records C) Pointers D) Stacks
13. A ……. is a data structure that organizes data similar to a line in the supermarket, where the first one in line is the first one out. A) Queue linked list B) Stacks linked list C) Both of them D) Neither of them
14. Which of the following is non-liner data structure? A) Stacks B) List C) Strings D) Trees
15. Herder node is used as sentinel in ….. A) Graphs B) Stacks C) Binary tree D) Queues
16. Which data structure is used in breadth first search of a graph to hold nodes? A) Stack B) queue C) Tree D) Array
17. Identify the data structure which allows deletions at both ends of the list but insertion at only one end. A) Input restricted dequeue B) Output restricted qequeue C) Priority queues D) Stack
18. Which of the following data structure is non linear type? A) Strings B) Lists C) Stacks D) Graph
19. Which of the following data structure is linear type? A) Graph B) Trees C) Binary tree D) Stack
20. To represent hierarchical relationship between elements, Which data structure is suitable? A) Dequeue B) Priority C) Tree D) Graph
21. A directed graph is ………………. if there is a path from each vertex to every other vertex in the digraph. A) Weakly connected B) Strongly Connected C) Tightly Connected D) Linearly Connected
22. In the …………….. traversal we process all of a vertex’s descendants before we move to an adjacent vertex. A) Depth First B) Breadth First C) With First D) Depth Limited
23. State True of False. i) Network is a graph that has weights or costs associated with it. ii) An undirected graph which contains no cycles is called a forest. iii) A graph is said to be complete if there is no edge between every pair of vertices. A) True, False, True B) True, True, False C) True, True, True D) False, True, True
24. Match the following. a) Completeness i) How long does it take to find a solution b) Time Complexity ii) How much memory need to perform the search. c) Space Complexity iii) Is the strategy guaranteed to find the solution when there in one. A) a-iii, b-ii, c-i B) a-i, b-ii, c-iii C) a-iii, b-i, c-ii D) a-i, b-iii, c-ii
25. The number of comparisons done by sequential search is ……………… A) (N/2)+1 B) (N+1)/2 C) (N-1)/2 D) (N+2)/2
26. In ……………, search start at the beginning of the list and check every element in the list. A) Linear search B) Binary search C) Hash Search D) Binary Tree search
27. State True or False. i) Binary search is used for searching in a sorted array. ii) The time complexity of binary search is O(logn). A) True, False B) False, True C) False, False D) True, True
28. Which of the following is not the internal sort? A) Insertion Sort B) Bubble Sort C) Merge Sort D) Heap Sort
29. State True or False. i) An undirected graph which contains no cycles is called forest. ii) A graph is said to be complete if there is an edge between every pair of vertices. A) True, True B) False, True C) False, False D) True, False
30. A graph is said to be ……………… if the vertices can be split into two sets V1 and V2 such there are no edges between two vertices of V1 or two vertices of V2. A) Partite B) Bipartite C) Rooted D) Bisects
31. In a queue, the initial values of front pointer f rare pointer r should be …….. and ……….. respectively. A) 0 and 1 B) 0 and -1 C) -1 and 0 D) 1 and 0
32. In a circular queue the value of r will be .. A) r=r+1 B) r=(r+1)% [QUEUE_SIZE – 1] C) r=(r+1)% QUEUE_SIZE D) r=(r-1)% QUEUE_SIZE
33. Which of the following statement is true? i) Using singly linked lists and circular list, it is not possible to traverse the list backwards. ii) To find the predecessor, it is required to traverse the list from the first node in case of singly linked list. A) i-only B) ii-only C) Both i and ii D) None of both
34. The advantage of …………….. is that they solve the problem if sequential storage representation. But disadvantage in that is they are sequential lists. A) Lists B) Linked Lists C) Trees D) Queues
35. What will be the value of top, if there is a size of stack STACK_SIZE is 5 A) 5 B) 6 C) 4 D) None
36. ………… is not the operation that can be performed on queue. A) Insertion B) Deletion C) Retrieval D) Traversal
37. There is an extra element at the head of the list called a ………. A) Antinel B) Sentinel C) List header D) List head
38. A graph is a collection of nodes, called ………. And line segments called arcs or ……….. that connect pair of nodes. A) Vertices, edges B) Edges, vertices C) Vertices, paths D) Graph node, edges
39. A ……….. is a graph that has weights of costs associated with its edges. A) Network B) Weighted graph C) Both A and B D) None A and B
40. In general, the binary search method needs no more than ……………. comparisons. A) [log2n]-1 B) [logn]+1 C) [log2n] D) [log2n]+1
41. Which of the following is not the type of queue? A) Ordinary queue B) Single ended queue C) Circular queue D) Priority queue
42. The property of binary tree is A) The first subset is called left subtree B) The second subtree is called right subtree C) The root cannot contain NULL D) The right subtree can be empty
43. State true or false. i) The degree of root node is always zero. ii) Nodes that are not root and not leaf are called as internal nodes. A) True, True B) True, False C) False, True D) False, False
44. Any node is the path from the root to the node is called A) Successor node B) Ancestor node C) Internal node D) None of the above
45. State true of false. i) A node is a parent if it has successor nodes. ii) A node is child node if out degree is one. A) True, True B) True, False C) False, True D) False, False
46. ………………. is not an operation performed on linear list a) Insertion b) Deletion c) Retrieval d) Traversal A) only a,b and c B) only a and b C) All of the above D) None of the above
47. Which is/are the application(s) of stack A) Function calls B) Large number Arithmetic C) Evaluation of arithmetic expressions D) All of the above
48. A …………… is an acyclic digraph, which has only one node with indegree 0, and other nodes have in-degree 1. A) Directed tree B) Undirected tree C) Dis-joint tree D) Direction oriented tree
49. …………………. Is a directed tree in which outdegree of each node is less than or equal to two. A) Unary tree B) Binary tree C) Trinary tree D) Both B and C
50. State true or false. i) An empty tree is also a binary tree. ii) In strictly binary tree, the out-degree of every node is either o or 2. A) True, False B) False, True C) True, True D) False, False
51. Which of the following data structures are indexed structures? A. Linear arrays B. Linked lists C. Queue D. Stack
52. Which of the following data structure store the homogeneous data elements? A. Arrays B. Records C. Pointers D. Lists
53. When new data are to be inserted into a data structure, but there is not available space; this situation is usually called …. A. Underflow B. overflow C. houseful D. saturated
54. A data structure where elements can be added or removed at either end but not in the middle is called … A. linked lists B. stacks C. queues D. dequeue
55. Operations on a data structure may be ….. A. creation B. destruction C. selection D. all of the above
56. The way in which the data item or items are logically related defines ….. A. storage structure B. data structure C. data relationship D. data operation
57. Which of the following are the operations applicable an primitive data structures? A. create B. destroy C. update D. all of the above
58. The use of pointers to refer elements of a data structure in which elements are logically adjacent is …. A. pointers B. linked allocation C. stack D. queue
59. Arrays are best data structures A. for relatively permanent collections of data B. for the size of the structure and the data in the structure are constantly changing C. for both of above situation D. for non of above situation
60. Which of the following statement is false? A. Arrays are dense lists and static data structure. B. Data elements in linked list need not be stored in adjacent space in memory C. Pointers store the next data element of a list. D. Linked lists are collection of the nodes that contain information part and next pointer.
61. Which of the following data structure is non-linear type? A) Strings B) Lists C) Stacks D) Tree
62. Which of the following data structure is linear type? A) Array B) Tree C) Graphs D) Hierarchy
63. The logical or mathematical model of a particular organization of data is called a ……… A) Data structure B) Data arrangement C) Data configuration D) Data formation
64. The simplest type of data structure is ……………… A) Multidimensional array B) Linear array C) Two dimensional array D) Three dimensional array
65. Linear arrays are also called ………………. A) Straight line array B) One-dimensional array C) Vertical array D) Horizontal array
66. Arrays are best data structures ………… A) For relatively permanent collections of data. B) For the size of the structure and the data in the structure are constantly changing C) For both of above situation D) For none of the above
67. Which of the following data structures are indexed structures? A) Linear arrays B) Linked lists C) Graphs D) Trees
68. Each node in a linked list has two pairs of ………….. and ………………. A) Link field and information field B) Link field and avail field C) Avail field and information field D) Address field and link field
69. A …………………… does not keep track of address of every element in the list. A) Stack B) String C) Linear array D) Queue
70. When does top value of the stack changes? A) Before deletion B) While checking underflow C) At the time of deletion D) After deletion
71. Which of the following data structure is non-linear type? A) Strings B) Lists C) Stacks D) Tree
72. Which of the following data structure is linear type? A) Array B) Tree C) Graphs D) Hierarchy
73. The logical or mathematical model of a particular organization of data is called a ……… A) Data structure B) Data arrangement C) Data configuration D) Data formation
74. The simplest type of data structure is ……………… A) Multidimensional array B) Linear array C) Two dimensional array D) Three dimensional array
75. Linear arrays are also called ………………. A) Straight line array B) One-dimensional array C) Vertical array D) Horizontal array
76. Arrays are best data structures ………… A) For relatively permanent collections of data. B) For the size of the structure and the data in the structure are constantly changing C) For both of above situation D) For none of the above
77. Which of the following data structures are indexed structures? A) Linear arrays B) Linked lists C) Graphs D) Trees
78. Each node in a linked list has two pairs of ………….. and ………………. A) Link field and information field B) Link field and avail field C) Avail field and information field D) Address field and link field
79. A …………………… does not keep track of address of every element in the list. A) Stack B) String C) Linear array D) Queue
80. When does top value of the stack changes? A) Before deletion B) While checking underflow C) At the time of deletion D) After deletion
91. Arrays are best data structures A) For relatively permanent collections of data B) For the size of the structure and the data in the structure are constantly changing C) For both of above situation D) For none of above situation
92. Which of the following data structure is not linear data structure? A) Arrays B) Linked lists C) Both of the above D) None of the above
93. The disadvantage in using a circular linked list is ……………………. A) It is possible to get into infinite loop. B) Last node points to first node. C) Time consuming D) Requires more memory space
94. A linear list in which each node has pointers to point to the predecessor and successors nodes is called as .. A) Singly Linked List B) Circular Linked List C) Doubly Linked List D) Linear Linked List
95. A ……………….. is a linear list in which insertions and deletions are made to from either end of the structure. A) Circular queue B) Random of queue C) Priority D) dequeue
96. In a priority queue, insertion and deletion takes place at ……………… A) Front, rear end B) Only at rear end C) Only at front end D) Any position
97. The time complexity of quick sort is ………….. A) O(n) B) O(n2) C) O(n log n) D) O(log n)
98. Which of the following is an application of stack? A) Finding factorial B) tower of Hanoi C) Infix to postfix conversion D) all of the above
99. The data structure which is one ended is ……………… A) Queue B) Stack C) Tree D) Graph
100. A list which displays the relationship of adjacency between elements is said to be A) Linear B) Non linear C) Linked list D) Trees
SATELLITE COMMUNICATION 1. Which of the following is the first active satellite? A. Echo I B. Telstar I C. Early Bird D. Sputnik I
2. Which of the following is the first commercial satellite? A. Early Bird B. Telstar C. Explorer D. Courier
3. What is the first passive satellite transponder? A. Sun B. Early Bird C. Score D. Moon
4. The first satellite to receive and transmit simultaneously A. Intelsat I B. Agila I C. Syncorn I D. Telstar I
5. A helical antenna is used for satellite tracking because of A. circular polarization B. maneuverability C. beamwidth D. gain
6. Repeaters inside communications satellites are known as A. Trancievers B. Transponders C. Transducers D. TWT
7. Considered as the unsolved problem in satellite system A. Coverage B. Cost C. Access D. Privacy
8. ______is a satellite that rotates around the earth in a low-altitude elliptical or circular pattern. A. Geosynchronous satellite B. Nonsynchronous satellite C. Prograde satellite D. Retrograde satellite
9. Is the geographical representation of a satellite antenna radiation pattern A. Footprint B. Spot C. Earth D. Region
10. The smallest beam of a satellite antenna radiation pattern A. Zone beam B. Hemispheric beam C. Spot beam D. Global beam
11. A satellite beam that covers almost 42.4% of the earths surface. A. Zone beam B. Hemispheric beam C. Spot beam D. Global beam
12. What is the frequency range of C-band? A. 8.5 to 12.5 GHz B. 3.4 to 6.425 GHz C. 12.95 to 14.95 GHz D. 27.5 to 31 GHz
13. A satellite signal transmitted from a satellite transponder to earth’s station. A. Uplink B. Downlink C. Terrestrial D. Earthbound
14. Collects very weak signals from a broadcast satellite A. Helical antenna B. Satellite dish C. LNA D. TWT
15. What is a device that detects both vertically and horizontally polarized signals simultaneously? A. Orthomode transducer B. Crystal detector C. Optoisolator D. Isomode detector
16. ______detects the satellite signal relayed from the feed and converts it to an electric current, amplifies and lower its frequency. A. Horn antenna B. LNA C. Satellite receiver D. Satellite dish
17. Is a loss of power of a satellite downlink signal due to earth’s atmosphere. A. Atmospheric loss B. Path loss C. Radiation loss D. RFI
18. What height must a satellite be placed above the surface of the earth in order for its rotation to be equal to earth’s rotation? A. 26,426.4 miles B. 27,426.4 miles C. 23,426.4 miles D. 22,426.4 miles
19. Point on the satellite obits closest to the earth. A. Apogee B. Perigee C. Prograde D. Zenith
20. The earth area covered by a satellite radio beam. A. Beamwidth B. Bandwidth C. Footprint D. Zone
21. What is the local oscillator (mixer) frequency of the satellite with an uplink frequency in GHz band? A. 3500 MHz B. 4500 MHz C. 2225 MHz D. 2555 MHz
22. What kind of battery panels are used in some advance satellites A. Germanium based panels B. Silicon based panel C. Galium Phosphate solar panel array D. Galium Arsenide solar panel array
23. Satellite engine uses A. jet propulsion B. ion propulsion system C. liquid fuel D. solar jet
24. A satellite batter has more power but lighter. A. Lithium B. Leclanche C. Hydrogen D. Magnesium
25. What kind of battery used by older satellites? A. Lithium B. Leclanche C. Hydrogen D. Magnesium
26. VSAT was made available in A. 1979 B. 1981 C. 1983 D. 1977
27. What band does VSAT first operate? A. L-band B. X-band C. C-band D. Ku-band
28. The first Philippine Mabuhay satellite has how many channels? A. 30 B. 24 C. 48 D. 50
29. The first Philippine Agila I will have how many transponders. A. 36 B. 48 C. 24 D. 12
30. How may satellite orbital slots are requested by the Philippine Government from ITU? A. 2 B. 4 C. 6 D. 8
31. The location of AsiaSat I. A. 105.5˚ East B. 151.5˚ East C. 115.5˚ East D. 170.5˚ East
32. AsiaSat I covers how many countries in Asia? A. 38 B. 10 C. 28 D. 15
33. The owner of AsiaSat 2 is A. Asia Satellite Telecommunications Company (ASTC) B. Japan Satellite System (JSAT) C. China Great Wall Industry Corporation D. Singapore Satellite Commision
34. What is the approximate path loss from satellite-to-earth station? A. 100 dB B. 150 dB C. 175 dB D. 200 dB
35. INTELSAT stands for A. Intel Satellite B. International Telephone Satellite C. International Telecommunications Satellite D. International Satellite
36. The frequency of Ku band for satellite communications. A. 6/4 GHz B. 14/11 GHz C. 12/14 GHz D. 4/8 GHz
37. A satellite cross-link means A. Earth-to-satellite link B. Satellite-to-earth link C. Satellite-to-satellite link D. None of these
38. Earth station uses what type of antenna A. Despun antenna B. Helical antenna C. Toroidal antenna D. Cassegrain antenna
39. What is the delay time for satellite transmission from earth transmitter to earth receiver? A. 0.5 s B. 1.0 s C. 5 ms D. 0.25 ms
40. The bandwidth of C-band satellite frequency band in U.S. A. 500 GHz B. 1000 GHz C. 1000 MHz D. 500 MHz
41. The most common device used as an LNA is A. zener diode B. tunnel diode C. IMPATT D. Shockley diode
42. The radiation patterns of earth coverage antennas have a beamwidth of approximately A. 21˚ B. 5˚ C. 17˚ D. 35˚
43. A mobile satellite array has usually how many elements? A. 6 B. 88 C. 12 D. 14
44. In a typical mobile satellite array antenna if three elements are activated, how many elements are deactivated? A. 3 B. 11 C. 5 D. 9
45. What circuit is responsible in activating and deactivating adjacent antenna elements in a mobile satellite array? A. Radial divider B. Divider/combiner C. Radial combiner D. Radial multiplexer
46. Most mobile satellite array uses ______in transforming 50 to 150 Ω impedance. A. stub B. balun C. quarter-wavelength transformer D. microstrip tapers.
47. The switching from one element to the other element in a typical mobile satellite array. A. Series B. Radial C. Matrix D. Shunt
48. A method of multiple accessing where a given RF channel bandwidth is divided inot smaller frequency band. A. CDMA B. ANIK-D C. TDMA D. FDMA
49. What is the delay time for satellite transmissions from earth transmitter to earth receiver? A. 0.5 s B. 1s C. 5 ms D. 0.25 s
50. As the height of a satellite orbit gets lower, the speed of the satellite ______. A. increases B. decreases C. remains the same D. None of the above
ANSWERS: 1. Sputnik I 2. Telstar 3. Early Bird 4. Telstar I 5. Circular polarization 6. Transponders 7. Privacy 8. Non synchronous satellite 9. Footprint 10. Spot beam 11. Global beam 12. 3.4 to 6.425 GHz 13. Downlink 14. Satellite dish 15. Orthomode transducer 16. LNA 17. Path loss 18. 22,426.4 miles 19. Perigee 20. Footprint 21. 2225 MHz 22. Galium Arsenide solar panel array 23. ion propulsion system 24. Lithium 25. Hydrogen 26. 1979 27. C-band 28. 30 29. 36 30. 6 31. 105.5˚ East 32. 38 33. China Great Wall Industry Corporation 34. 200 dB 35. International Telecommunications Satellite 36. 14/11 GHz 37. Satellite-to-satellite link 38. Cassegrain antenna 39. 0.5 s 40. 500 MHz 41. tunnel diode 42. 17˚ 43. 14 44. 11 45. Radial divider 46. quarter-wavelength transformer 47. Shunt 48. FDMA 49. 0.5 s 50. Increases RADIO RECEIVERS 1. Indicate which of the following statements about the advantages of the phase discriminator over the slope detector is false: A. Much easier alignment B. Better linearity C. Greater limiting D. Fewer tuned circuits ANSWER: C
2. Show which of the following statements about the amplitude limiter is untrue: A. The circuit is always biased in class C, by virtue of the leak-type bias. B. When the input increases past the threshold of the limiting, the gain decreases to keep the output constant. C. The output must be tuned D. Leak-type bias must be used ANSWER: A
3. In a radio receiver with simple AGC A. an increase in signal strength produces more AGC B. the audio stage gain is normally controlled by the AGC C. the faster the AGC time constant the more accurate the output D. the highest AGC voltage is produced ANSWER: A
4. In a broadcast super heterodyne receiver, the A. local oscillator operates below the signal frequency B. mixer input must be tuned to the signal frequency C. local oscillator frequency is normally double the IF D. RF amplifier normally works at 455 kHz above the carrier frequency ANSWER: B
5. To prevent overloading of the IF amplifier in a receiver, one should use A. squelch B. variable sensitivity C. variable selectivity D. double conversion ANSWER: B
6. A superheterodyne receiver with an IF of 450 kHz is tuned to a signal at 1200 kHz. The image frequency is A. 750 kHz B. 900 kHz C. 1650 kHz D. 2100 kHz ANSWER: D
7. In a ratio detector A. the linearity is worse than in phase discriminator B. stabilization against signal strength variations is provided C. the output is twice that obtainable from a similar phase discriminator D. the circuit is the same as in a discriminator, except that the diodes are reversed ANSWER: A
8. The typical squelch circuit cuts off A. an audio amplifier when the carrier is absent B. RF interference when the signal is weak C. An IF amplifier when the AGC is maximum D. An IF amplifier when the AGC is minimum ANSWER: A
9. Indicate the false statement in connection with communications receivers. A. The noise limiter cuts off the receiver’s output during a noise pulse. B. A product demodulator could be used for the reception of Morse code. C. Double conversion is used to improve image rejection D. Variable sensitivity is used to eliminate selective fading ANSWER: D
10. The controlled oscillator synthesizer is sometimes preferred over the direct one because A. it is a simpler piece of equipment B. its frequency stability is better C. it does not require crystal oscillator D. it is relatively free of spurious frequency ANSWER: D
11. The frequency generated by each decade in a direct frequency synthesizer is much higher than the frequency shown; this is done to A. reduce the spurious frequency problem B. increase the frequency stability of the synthesizer C. reduce the number of decades D. reduce the number of crystals required ANSWER: A
12. Indicate which of the following circuits could not demodulate SSB: A. Balance modulator B. Product modulator C. BFO D. Phase discriminator ANSWER: D
13. If a FET is used as the first AF amplifier in a transistor receiver, this will have the effect of A. improving the effectiveness of the AGC B. reducing the effect of negative-peak clipping C. reducing the effect of noise at low modulation depths D. improving the selectivity of the receiver ANSWER: B
14. Indicate the false statement. The superheterodyne receiver replaced the TRF receiver because the latter suffered from A. gain variation over the frequency coverage range B. insufficient gain and sensitivity C. inadequate selectivity at high frequencies D. instability ANSWER: B
15. The image frequency of a superheterodyne receiver A. is created within the receiver itself B. is due to insufficient adjacent channel rejection C. is not rejected be the IF tuned circuits D. is independent of the frequency to which the receiver is tuned ANSWER: C
16. One of the main functions of the RF amplifier in a superheterodyne receiver is to A. provide improved tracking B. permit better adjacent-channel rejection C. increase the tuning range of the receiver D. improve the rejection of the image frequency ANSWER: D
17. A receiver has poor IF selectivity. It will therefore also have poor A. blocking B. double-spotting C. diversion reception D. sensitivity ANSWER: A
18. Three-point tracking is achieved with A. variable selectivity B. the padder capacitor C. double spotting D. double conversion ANSWER: B
19. The local oscillator of a broadcast receiver is tuned to a frequency higher than the incoming frequency A. to help the image frequency rejection B. to permit easier tracking C. because otherwise an intermediate frequency could not be produced D. to allow adequate frequency coverage without switching ANSWER: D
20. If the intermediate frequency is very high (indicate false statement) A. image frequency rejection is very good B. the local oscillator need not be extremely stable C. the selectivity will be poor D. tracking will be improved ANSWER: D
21. A low ratio of the ac to the dc load impedance of a diode detector results in A. diagonal clipping B. poor AGC operation C. negative-peak clipping D. poor AF response ANSWER: C
22. One of the following cannot be used to demodulate SSB: A. Product detector B. Diode Balance modulator C. Bipolar transistor balanced modulator D. Complete phase-shift generator ANSWER: C
23. Indicate the false statement. Noting that no carrier is transmitter with J3E, we see that A. the receiver cannot use a phase comparator for AFC B. adjacent-channel rejection is more difficult C. production of AGC is a rather complicated process D. the transmission is not compatible with A3E ANSWER: B
24. When a receiver has good blocking performance, this means that A. it does not suffer from double-spotting B. its image frequency rejection is poor C. it is unaffected by AGC derived from nearby transmissions D. its detector suffers from burnout ANSWER: B
25. An AM receiver uses a diode detector for demodulation. This enables it satisfactorily to receive A. single-sideband, suppressed-carrier B. single-sideband, reduced-carrier C. ISB D. Single-sideband, full-carrier ANSWER: D MICROWAVE COMMUNICATION 1. ______is the progressive decrease of signal strength with increasing distance. A. Radiation B. Attenuation C. Modulation D. Propagation
2. Calculate the effective earth’s radius if the surface refractivity is 301. A. 8493 km B. 8493 mmi C. 6370 km D. 6370 mi
3. If k-factor is greater than 1, the array beam is bent A. Away from the earth B. towards the ionosphere, C. towards the earth D. towards the outer space
4. The antenna separations (in meters) required for optimum operation of a space diversity system can be calculated from: A. S = 2λR/L B. S = 3λR/L C. S = λR/RL D. S = λR/L where R = effective earth radius (m) and L = path length (m)
5. Rainfall is an important factor for fading of radio waves at frequencies above A. 10 GHz B. 100 GHz C. 1 GHz D. 100 MHz
6. Theoretically electromagnetic radiation field strength varies in inverse proportion to the square of the distance, but when atmospheric attenuation effects and the absorption of the terrain are taken into account the attenuation can be as high as the inverse ______power of the distance. A. Third B. Fourth C. Fifth D. Sixth
7. What do you call an attenuation that occurs over many different wavelengths of the carrier? A. Rayleigh fading B. Rician fading C. Wavelength fading D. Slow fading
8. Which of the reception problems below that is not due to multipath? A. Delayed spreading B. Rayleigh fading C. Random Doppler shift D. Slow fading
9. Which causes multipath or frequency-selective fading? A. Small reflector B. Nearer reflector C. Further reflector D. Large reflector
10. In microwave transmission using digital radio, what causes most intersymbol interference? A. Delayed spreading B. Rayleigh fading C. Random Doppler shift D. Slow fading
11. A shipboard equipment which measures the distance between the ship’s bottom and the ocean floor. A. Fathometer B. Echosounder C. LORAN D. SONAR
12. The cavity resonator A. Is equivalent to an LC resonant circuit B. In a reflect klystron has its output taken from the reflector plate C. Produces a frequency which is independent of the cavity size. D. Has a low Q factor for narrow operation.
13. At what position is the input signal inserted into a traveling-wave tube? A. At the cathode end of the helix B. At the collector C. At the collector end of the helix D. At the control grid of the electron gun
14. Coupling into and out of a traveling-wave tube can be accompanied by a A. Waveguide match B. Cavity match C. Direct coax-helix match D. All of the above
15. A high-power microwave pulse of the order of megawatts can be generated by a A. traveling-wave tube B. magnetron C. reflex klystron D. Gunn diode
16. A traveling-wave tube (TWT) amplifies by virtue of A. The absorption of energy by the signal from an electron stream B. The effect of an external magnetic field C. The energy contained the cavity resonators D. The energy liberated from the collector
17. What is the purpose of the electromagnetic field which surrounds a traveling-wave tube? A. To accelerate the electron B. To velocity modulate the electron beam C. To keep the electrons from spreading out D. To slow down the signal on the helix
18. Which of the following is used as an oscillator device in the SHF band? A. Thyratron tube B. Tunnel diode C. Klystron tube D. Both B and C
19. Microwave frequencies are normally regarded as those in the range of A. 1 to 500 MHz B. 1000 to 10,000 GHz C. 1 to 100 GHz D. 10 to 1000 GHz
20. The highest frequency which a conventional vacuum-tube oscillator can generate is not limited by the A. Electron transit time B. Distributed lead inductance C. Inter-electrode capacitance D. Degree of emission from the cathode
21. As the electron beam moves through a klystron’s intercavity drift space A. Frequency modulation at the input cavity creates velocity modulation at the output cavity B. Velocity modulation at the input cavity creates density modulation at the output cavity C. Density modulation at the input cavity creates velocity modulation at the output cavity D. Phase modulation at the input cavity creates velocity modulation at the output cavity.
22. The frequency of the oscillation generated by a magnetron, is mainly determined by A. The flux density of the external magnet B. The ratio of the dc cathode voltage to the magnetic flux density C. The number of the cavity resonators D. The dimension of each cavity resonator
23. If the instantaneous RF potentials on the two sides of a magnetron cavity are of opposite polarity, the operation is in the A. π mode B. π/2 mode C. 2π mode D. π/4 mode
24. The Gunn diode oscillator A. Is capable of generating continuous microwave power of the order of kilowatt B. Generates frequencies which are below 100 MHz C. Operates over a positive resistance characteristic D. Depends on the formation of charge domain
25. What ferrite device can be used instead of duplexer of isolate microwave transmitter and receiver when both are connected to the same antenna? A. Isolator B. Magnetron C. Simplex D. Circulator
26. To achieve good bearing resolution when using a pulsed-radar set, an important requirement is A. A narrow, antenna-beam width in the vertical plane B. A narrow, antenna-beam width in the horizontal plane C. A low repetition rate D. A high duty cycle
27. When used in conjunction with a radar set, the purpose of an echo box is to provide an artificial target. A. Which may be used to tune the radar synchronizer B. Which may be used to tune the radar receiver C. To the tone of the pulse repetition D. Tune the magnetron to the correct frequency
28. In a radar-set receiver, the usual mixer stage is A. And FET B. A tunnel diode C. A silicon crystal D. A Rochelle salts crystal
29. Klystron oscillators are most often used in the frequency range of A. 300 to 3000 MHz B. 3000 to 30000 MHz C. 30 to 30000 MHz D. 10 to 10000 MHz
30. Oscillators of a klystron tube are maintained A. By bunches of electrons passing the cavity grids B. By plate-to-cathode feedback C. By feedback between the accelerating grid and the repeller D. By circulating bunches of electrons within the cavities.
31. What allow microwave to pass in only one direction? A. RF emitter B. Capacitor C. Varactor-triac D. Ferrite emitter
32. In an SHF pulsed radar set, a reflex klystron can be used as a A. Single mixer stage B. Local oscillator C. Transmitter oscillator D. Duplexer stage
33. A Class-S Emergency Position-Indicating Radio Beacon (E.P.I.R.B) A. Must be capable of floating or being secured to a survival B. Must have its battery replaced after emergency use C. May be tested during the first five minutes of any hour D. All of these
34. A PPI cathode-ray tube as used on a radar set A. Is used to check the percentage of modulation B. Indicates both the range and azimuth of a target C. Indicates only the range of a target D. Is used for receiver alignment
35. The resonant frequency of a cavity resonator depends upon A. The mode of operation B. Its electrical dimensions C. Its physical dimensions D. The capacitor which tunes it
36. The maximum usable range of the usual radar set (on any particular range setting) is determined by A. The width of the transmitted pulses B. The interval between transmitted pulses C. The bandwidth of the receiver IF stages D. The duty cycle
37. A reflex klystron is oscillating at the frequency of its resonant cavity. If the reflector voltage is made slightly less negative, the A. Oscillation will cease B. Output power would increase C. The frequency will decrease D. Bunching would occur earlier in time
38. The coarse frequency adjustment of a reflex klystron is accomplished by A. The AFC system B. Adjusting the flexible wall of the resonant cavity C. An adjustment in the synchronizer D. Varying the repeller voltage
39. In a pulsed radar set, the STC circuit is used to A. Improve the target bearing resolution B. Increases receiver sensitivity for echoes from targets C. Vary the pulse frequency in order to control the maximum target D. Reduce interference from the effects of sea return
40. In a pulsed radar set, the function of the duplexer is to A. Aid in calibrating the display unit B. Prevent frequency drift in the klystron C. Allow the transmitter and the receiver to operate from a common antenna D. All of these
41. A magnetron is operated at a duty cycle of 0.001. It has a peak power output of 100 kilowatts. Its average power is A. 10,000 watts B. 100 watts C. 1,000 watts D. 1,000,000 watts
42. The aquadag coating on the inside of PPI tube is used A. To focus the beam of primary electrons B. To shield the electron beam from unidirectional magnetic C. As a second anode and to prevent the build-up of secondary field D. All of these
43. If the duration of the radar transmitted pulse, on a particular range of operation, is increased, the required bandwidth of the receiver’s IF amplifiers A. Must remain as before B. Must be increased C. May be decreased D. Must be doubled
44. The main frequency determining element of a klystron is A. The repeller voltage B. The accelerating voltage C. Its resonant cavity D. Its mode of operation
45. A thin layer of dirt and grime coverts the reflecting surface of the parabolic dish of a radar set. The particular effect on the performance of the radar will be A. A decrease in range B. A reduction in horizontal resolution C. No noticeable effect D. A decrease in gain
46. Which of the following permits a microwave signal to travel in one direction with virtually no loss, but severely attenuates any signal attempting to travel in the reverse direction? A. Isolator B. Wave trap C. Tunnel diode D. Circulator
47. It is possible to increase the maximum range of a radar equipment by A. Lowering the pulse frequency B. Raising the peak power of the transmitter C. Narrowing the beam width and increasing the pulse duration D. All of these
48. When it is desired that short-range targets be clearly seen on a pulsed-radar set, it is important that the receiver and display system have A. A long time constant B. Low-pass filters C. The shortest possible time D. The restricted high-frequency response
49. Which of the following is used as a high power microwave oscillator? A. Thyratron B. Magnetron C. Klystron D. Reflex-klystron
50. Which of the following operating frequencies is used for the modern loran navigational system? A. Loran C: 100 kHz B. Loran D: 10.2 kHz C. Loran A: 1950 kHz D. Loran B: 900 kHz
ANSWERS :: 1. Attenuation 2. 8493 km 3. towards the earth 4. S = 3λR/L 5. 10 GHz 6. Sixth 7. Slow fading 8. Slow fading 9. Large reflector 10. Delayed spreading 11. SONAR 12. Is equivalent to an LC resonant circuit 13. ± 2000 Hz 14. All of the above 15. magnetron 16. The absorption of energy by the signal from an electron stream 17. To keep the electrons from spreading out 18. Both B and C 19. 1 to 100 GHz 20. Degree of emission from the cathode 21. Velocity modulation at the input cavity creates density modulation at the output cavity 22. The dimension of each cavity resonator 23. π mode 24. Depends on the formation of charge domain 25. Circulator 26. A narrow, antenna-beam width in the horizontal plane 27. Which may be used to tune the radar receiver 28. A silicon crystal 29. 3000 to 30000 MHz 30. By bunches of electrons passing the cavity grids 31. Ferrite emitter 32. Local oscillator 33. All of these 34. Indicates both the range and azimuth of a target 35. Its physical dimensions 36. The interval between transmitted pulses 37. The frequency will decrease 38. Adjusting the flexible wall of the resonant cavity 39. Reduce interference from the effects of sea return 40. Allow the transmitter and the receiver to operate from a common antenna 41. 100 watts 42. As a second anode and to prevent the build-up of secondary field 43. May be decreased 44. Its resonant cavity 45. No noticeable effect 46. Isolator 47. All of these 48. The shortest possible time 49. Magnetron 50. Loran C: 100 kHz MICROPROCESSORS 1. The minimum number of transistors required to implement a two input AND gate is A. 2 B. 4 C. 6 D. 8 Answer: C
2. Using DeMorgan’s Theorem we can convert any AND-OR structure into A. NAND-NAND B. OR-NAND C. NAND-NOR D. NOR-NAND Answer: A
3. For a memory with a 16-bit address space, the addressability is A. 16 bits B. 8 bits C. 2^16 bits D. Cannot be determined Answer: D
4. Because we wish to allow each ASCII code to occupy one location in memory, most memories are _____ addressable. A. BYTE B. NIBBLE C. WORD (16 bits) D. DOUBLEWORD (32 bits) Answer: A
5. Circuit A is a 1-bit adder; circuit B is a 1 bit multiplier. A. Circuit A has more gates than circuit B B. Circuit B has more gates than circuit A C. Circuit A has the same number of gates as circuit B (Hint: Construct the truth table for the adder and the multiplier) Answer: A
6. When the write enable input is not asserted, the gated D latch ______its output. A. can not change B. clears C. sets D. complements Answer: A
7. A structure that stores a number of bits taken “together as a unit” is a A. gate B. mux C. decoder D. register Answer: D
8. We say that a set of gates is logically complete if we can build any circuit without using any other kind of gates. Which of the following sets are logically complete A. set of {AND,OR} B. set of {EXOR, NOT} C. set of {AND,OR,NOT} D. None of the above Answer: C
9. Of the following circuits, the one which involves storage is A. RS Latch B. mux C. nand D. decoder Answer: A
10. If the number of address bits in a memory is reduced by 2 and the addressability is doubled, the size of the memory (i.e., the number of bits stored in the memory) A. doubles B. remains unchanged C. halves D. increases by 2^(address bits)/addressability Answer : C
12. If m is a power of 2, the number of select lines required for an m-input mux is: A. m B. 2^m C. log2 (m) D. 2*m Answer: C
13. For the number A[15:0] = 0110110010001111, A[14:13] is ______A[3:2]. A. less than B. greater than C. the same as d . cannot be determined Answer: C
14. Which of the following conditions is not allowed in an RS latch? A. R is asserted, S is asserted B. R is asserted, S is negated C. R is negated, S is asserted D. R is negated, S is negated Answer: A
15. Which of the following pair of gates can form a latch? A. a pair of cross coupled OR B. a pair of cross copled AND C. a pair of cross coupled NAND D. a cross coupled NAND/OR Answer: C
16. ‘Burst refresh’ in DRAM is also called A. Concentrated refresh B. Distributed refresh C. Hidden refresh D. None of the above Answer: A
17. The number of interrupt lines in 8085 is A. 2 B. 3 C. 4 D. 5 Answer: D
18. A real number consists of A. integer part B. integer part and fraction part C. integer part, fraction part along with positive or negative sign D. none of the above Answer: C
19. Assertion (A): Negative values of incremental operator in DO loop are allowed in Fortran 77 but not in earlier versions of Fortran. Reason (R): Fortran 77 has better array facilities than earlier versions of Fortran. A. Both A and R are correct and R is correct explanation of A B. Both A and R are correct but R is not correct explanation of A C. A is correct R is wrong D. A is wrong R is correct Answer: B
20. Which of the following is not treated as hexadecimal constant by assembler in 8085? A. 45 H B. 6 AFH C. 234 D. 64 H Answer: C
21. IC 7485 cannot be cascadeD. A. True B. False Answer: B
22. An I/O processor controls the flow of information between A. cache memory and I/O devices B. main memory and I/O devices C. two I/O devices D. cache and main memory Answer: B
23. MS Access is a DBMS software. A. True B. False Answer: A 24. When .9432 E – 4 is subtracted from .5452 E – 3 in normalized floating point mode A. none of the numbers is changed B. .9432 E – 4 is changed to .09432 E – 3 and .5452 E – 3 is not changed C. .5452 E – 3 is changed to 5.452 E – 4 but .9432 E – 4 is not changed D. both Ihe numbers are changed and their exponents are, made equal to -5 Answer: B
25. DS directive in 8085 A. forces the assembler to reserve one byte of memory B. forces the assembler to reserve a specified number of bytes in the memory C. forces the assembler to reserve a specified number of consecutive bytes in the memory D. none of the above Answer: C
26. Which of the following is a valid integer constant? A. 127 B. 127.0 C. 127 D. 125 + 3 Answer: A
27. The five flags in 8085 are designated as A. Z, CY, S, P and AC B. D, Z, S, P, AC C. Z, C, S, P, AC D. Z, CY, S, D, AC Answer: A
28. In 8085 which addressing mode is also called inherent addressing? A. Direct B. Register C. Implicit D. Immediate Answer: C
29. It is possible to copy a file in the same directory. A. True B. False Answer: A
30. In a computer the data transfer between hard disk and CPU is nearly the same as that between diskette and CPU. A. True B. False Answer: B
31. The timing difference between a slow memory and fast processor can be resolved if A. processor is capable of waiting B. external buffer is used C. either (a) or (b) D. neither (a) nor (b) Answer: C
32. In 8086 the number of bytes which can be addressed directly is about A. 1000 B. 10000 C. 100000 D. one million Answer: D
33. In Fortran 77 a variable name can contain special characters. A. True B. False Answer: B
34. Which of the following is not a general purpose peripheral? A. I/O port B. Programmable interrupt controller C. Programmable CRT controller D. Programmable interval timer Answer: C
35. Each instruction in assembly language program has the following fields: Lable field Mnemonic field Operand field Comment field The correct sequence of these fields is? A. 1, 2, 3, 4 B. 1, 2, 4, 3 C. 2, 1, 3, 4 D. 2, 1, 4, 3 Answer: A
36. In one’s complement 8 bit representation 11111111 represents A. +0 B. -0 C. +1 D. -1 Answer: B
37. The operating modes of 8255 A are called A. mode 0 and mode 1 B. mode 0, mode 1 and mode 2 C. mode 0 and mode 2 D. mode 0, mode 2 and mode 3 Answer: B
38. Which of the following is type declaration statement in C? A. int bar B. s = s + 1 C. king = horse + 1 D. prin = prin * prin Answer: A
39. Internet is a worldwide network of computers where most of the information is freely available. A. True B. False Answer: A
40. A 37 bit mantissa has an accuracy of A. 6 decimal places B. 8 decimal places C. 10 decimal places D. 11 decimal places Answer: D
41. In a C expression using assignment operators, relational operators and arithmetic operators, the hierarchy of operations (in the absence of parenthesis) is A. assignment, relational, arithmetic B. relational, assignment, arithmetic C. arithmetic, assignment, relational D. arithmetic, relational, assignment Answer: D
42. In 8085, the pins for SID and SOD are A. 4 and 5 respectively B. 5 and 4 respectively C. 3 and 4 respectively D. 4 and 3 respectively Answer: B
43. Assertion (A): Each memory chip has its own address latch. Reason (R): ALE signal comes out of microprocessor 8085 and goes to memory chip. A. Both A and R are correct and R is correct explanation of A B. Both A and R are correct but R is not correct explanation of A C. A is correct R is wrong D. A is wrong R is correct Answer: D
44. An e-mail message can be sent to many recipients. A. True B. False Answer: A
45. In C the keywords are also called A. special words B. reserved words C. class words D. character words Answer: B
46. The character set of Fortran 77 includes lower case alphabets a to z. A. True B. False Answer: B
47. Which memory has read operation, byte erase, byte write and chip erase? A. RAM B. UVEPROM C. EEPROM D. both (b) and (c) Answer: C
48. The forms of IF statements in FORTRAN 77 are called A. logical IF and Block IF B. logical IF, block IF and arithmetic IF C. logic IF, block IF, arithmetic IF and negate IF D. logical IF and arithmetic IF Answer: B
49. In 8085 A. P flag is set when the result has even parity B. P flag is set when the result has odd parity C. P flag is reset when the result has odd parity D. P flag is reset when the result has even parity Answer: A
50. If the sign bit of mantissa is 0 and the exponent is increased from a positive to a more negative number the result is A. a larger floating point number B. a smaller floating point number C. either (a) or (b) depending on the actual number D. a negative floating point number Answer: A MATERIALS and COMPONENTS 1. The dielectric losses do not depend on frequency. A. True B. False Answer: B
2. Fleming’s left hand rule is used to find A. direction of force on a current carrying conductor B. direction of flux in solenoid C. direction of magnetic field due to a current carrying conductor D. direction of induced emf Answer: A
3. The rule that resistivity of conductors can be separated into two parts viz. temperature independent and temperature dependent is known as A. Matthiessen’s rule B. Debye rule C. Curie rule D. Onne’s rule Answer: A
4. Above a certain temperature, the specific heat of a metal becomes constant. This temperature is called A. Debye temperature B. Curie temperature C. Neel temperature D. Transition temperature Answer: A
5. A dielectric material must be A. insulator B. good conductor C. resistor D. semiconductor Answer: A
6. Spontaneous magnetisation is characteristic of ferromagnetic materials. A. True B. False Answer: A
7. An atom of a rare gas is placed is an electric field E. Then A. the nucleus will be shifted in the direction of E by an amount which is proportional to E. B. the nucleus will not be shifted. C. the nucleus will be shifted in the direction of E by an amount which is independent of E. D. the nucleus will be shifted in a direction opposite to that of E. Answer: A
8. In Vander walls crystals, there exists a high degree of stability of the outer electron shell. A. True B. False Answer: A
9. As per temperature limits, the number of categories of solid dielectrics are A. 7 B. 6 C. 8 D. 5
10. At room temperature the number of conducting electrons in an intrinsic semiconductor A. is almost equal to the number of valence electrons B. is about half the number of valence electrons C. is small as compared to the number of valence electrons D. is a very small fraction of the number of valence electrons Answer: D
11. A characteristic property of crystal is its periodicity of structure. A. True B. False Answer: A
12. For making a capacitor it is better to have a dielectric having A. high permittivity B. low permittivity C. permittivity same as that of air D. permittivity which is neither high nor low Answer: A
13. In solid insulator materials having only one kind of atom, the types of polarization which exist are A. electronic only B. electronic and ionic C. electronic, ionic and permanent D. electronic and permanent Answer: A
14. Schrodinger wave equation is a A. linear equation B. differential equation C. partial differential equation D. none of the above Answer: C
15. Debye temperature of metals is A. about 10 K B. about 200 K C. about 600 K D. about 2 K Answer: B
16. As the viscosity of a liquid increases, the relaxation time A. remains constant B. increases C. decreases D. First decreases then increases Answer: B
17. The materials which become polarized on the application of mechanical stress are called piezoelectric. A. True B. False Answer: A 18. Which inductor is linear? A. Air cored B. Cast iron cored C. Sheet steel cored D. Iron alloy cored Answer: A
19. Which inductor is used at high frequencies? A. Cast iron cored B. Sheet steel cored C. Iron alloy cored D. Ceramic cored Answer: D
20. On the basis of the type of chemical bonds, solids may be classified into A. ionic crystals B. ionic and valence crystals C. ionic crystal, valence crystals and metals D. ionic crystals, valence crystals, metal and vander wall crystals Answer: D
21. A leakage capacitor can be represented by a capacitance C and resistance R in parallel C. A. True B. False Answer: A
22. Electric dipole moment is expressed in debye unit. A. True B. False Answer: A
23. A vacant electronic state moves in the same direction as would a positive charge carrier. A. True B. False Answer: A
24. Piezoelectricity means the slight change in dimensions of a specimen when an electric field is applied. A. True B. False Answer: A
25. Many compounds also exhibit semiconducting properties. A. True B. False Answer: A
26. In a metal, the valence electrons A. are not shared B. are shared only between neighbouring atoms C. are shared by all atoms D. either (b) or (c) Answer: C
27. The number of protons in a silicon atom are A. 4 B. 8 C. 12 D. 14 Answer: D
28. The fact that domains exhibits spontaneous magnetisation is A. First hypothesis is of Curie B. Second hypothesis is of Weiss C. Curie-Weiss law D. Boltzmann’s statistics Answer: B
29. the most important set of specifications of transformer oil include A. dielectric strength and viscosity B. dielectric strength and flash point C. viscosity and flash point D. flash point and viscosity Answer: A
30. Nickel is a non-magnetic material. A. True B. False Answer: B
31. With increase in temperature, the electrical conductivity would A. increase in metals as well as in intrinsic semiconductor B. increase in metals but decrease in intrinsic semiconductor C. decrease in metals but increase in intrinsic semiconductor D. decrease in metals as well as in intrinsic semiconductor Answer: C
32. If a small amount of Cu is added to Ni conductor, then A. resistivity of Ni will decrease at all temperatures because Cu is a better conductor than Ni B. residual resistivity of Ni at low temperature will increase as Cu atoms act as defect centres C. resistivity of Ni will increase at all temperatures as Cu destroys the periodicity of Ni and acts as defects D. resistivity of Ni remains the same Answer: C
33. When a dielectric material is subjected to alternating field, the absorption of energy by the material from the field is given by the imaginary part of polarizability. A. True B. False Answer: A
34. Which of the following are true for relative dielectric constant? 1. It is dimensionless. 2. It is equal to 1 for vacuum. 3. It is equal to 1 for all substances. A. 1 and 2 only B. 2 and 3 only C. 1 and 3 only D. 1, 2 and 3 Answer: A
35. Hall effect is observed in a specimen (metal or semi- conductor) when it is carrying current and is placed in a magnetic field. The resultant electric field inside the specimen is A. normal to both current and magnetic field B. in the same direction as current C. in a direction anti parallel to magnetic field D. none of the above Answer: A
36. The merger of hole and free electron is called A. covalent bonding B. recombination C. thermal energy D. free electrons Answer: B
37. Wood is a diamagnetic material. A. True B. False Answer: B
38. The unit for mmf is A. A B. Wb C. T D. V Answer: A
39. A magnetic field exists around A. moving charges B. static charges C. iron D. copper Answer: A
40. The residual resistivity of a binary alloy at 0 K is A. sum of residual resistivities of component metals B. difference of residual resistivities of component metals C. product of residual resistivities of component metals D. dependent on the concentration of minor component in the alloy Answer: D
41. The resistance of a photoconductor A. increases with increase in light intensity B. decreases with increase in light intensity C. may increase or decrease with increase in light intensity D. remains constant Answer: B
42. If the number of atoms per unit volume of a monoatomic gas changes, the dielectric constant still remains constant. A. True B. False Answer: A
43. The number of protons in a copper atom are A. 2 B. 9 C. 11 D. 29 Answer: D
44. When a material is in superconducting state and a magnetic field is applied A. the superconducting property is not affected B. the superconducting property may be affected and resistivity may increase from zero to a low value C. the superconducting property may be destroyed D. the material may become an insulator Answer: C
45. The elements which become superconducting at extremely low temperatures are A. good conductors at room temperature B. ferromagnetic at room temperature C. relatively poor conductors at room temperature D. insulators at room temperature Answer: C
46. Electrical contact materials used in switches, brushes, relay must possess A. high thermal conductivity and high melting point B. low thermal conductivity and low melting point C. high thermal conductivity and low melting point D. low thermal conductivity and high melting point Answer: A
47. The phenomenon of dielectric hysteresis occurs with A. dc B. ac C. both ac and dc D. none of the above Answer: B
48. As the atoms of rare gases become larger, electronic polarizability A. increases B. decreases C. remains the same D. may increase or decrease Answer: C
49. In an intrinsic semiconductor, at a given temperature T A. the number of electrons-hole pairs generated per second due to thermal motion are equal to the number of electron-hole pairs lost per second due to recombination B. the number of electron-hole pairs generated per second due to thermal motion is always less than the number of electron-hole pairs lost per second due to recombination C. the number of electron hole pairs generated per second due to thermal motion is always more than the number of electron-hole pairs lost per second due to recombination D. any of the above Answer: A
50. Ferrimagnetic materials have anti-parallel orientation of equal moments of permanent dipoles. A. True B. False Answer: A ELECTRONIC DEVICES and CIRCUITS 1. At room temperature the current in an intrinsic semiconductor is due to A. holes B. electrons C. ions D. holes and electrons Answer: D
2. Work function is the maximum energy required by the fastest electron at 0 K to escape from the metal surface. A. True B. False Answer: B
3. The most commonly used semiconductor material is A. silicon B. germanium C. mixture of silicon and germanium D. none of the above Answer: A
4. In which of these is reverse recovery time nearly zero? A. Zener diode B. Tunnel diode C. Schottky diode D. PIN diode Answer: C
5. A transistor has a current gain of 0.99 in the CB mode. Its current gain in the CC mode is A. 100 B. 99 C. 1.01 D. 0.99 Answer: A
6. The amount of photoelectric emission current depends on A. frequency of incident radiation B. intensity of incident radiation C. both frequency and intensity of incident radiation D. none of the above Answer: B
7. Assertion (A): A p-n junction has high resistance in reverse direction. Reason (R): When a reverse bias is applied to p-n junction, the width of depletion layer increases. A. Both A and R are true and R is correct explanation of A B. Both A and R are true but R is not a correct explanation of A C. A is true but R is false D. A is false but R is true Answer: A
8. Voltage series feedback (Also called series-shunt feedback) results in A. increase in both I/P and O/P impedances B. decrease in both I/P and O/P impedances C. increase in I/P impedance and decrease in O/P impedance D. decrease in I/P impedance and increase in O/P impedance Answer: C
9. How many free electrons does a p type semiconductor has? A. only those produced by thermal energy B. only those produced by doping C. those produced by doping as well as thermal energy D. any of the above Answer: A
10. Which of the following has highest resistivity? A. Mica B. Paraffin wax C. Air D. Mineral oil Answer: C
11. Assertion (A): In p-n-p transistor collector current is termed negative. Reason (R): In p-n-p transistor holes are majority carriers. A. Both A and R are true and R is correct explanation of A B. Both A and R are true but R is not a correct explanation of A C. A is true but R is false D. A is false but R is true Answer: B
12. The sensitivity of human eyes is maximum at A. white portion of spectrum B. green portion of spectrum C. red portion of spectrum D. violet portion of spectrum Answer: B
13. In a bipolar transistor, the base collector junction has A. forward bias B. reverse bias C. zero bias D. zero or forward bias Answer: B
14. An intrinsic silicon sample has 1 million free electrons at room temperature. As the temperature is increased A. the number of free electrons increases B. the number of free electrons increases but the number of holes decreases C. the number of free electrons and holes increase by the same amount D. the number of free electrons and holes increase but not by the same amount Answer: C
15. What is the necessary a.c. input power from the transformer secondary used in a half wave rectifier to deliver 500 W of d.c. power to the load? A. 1232 W B. 848 W C. 616 W D. 308 W Answer: A
16. In a semi-conductor diode, the barrier offers opposition to A. holes in P-region only B. free electrons in N-region only C. majority carriers in both regions D. majority as well as minority carriers in both regions Answer: C
17. In a half wave rectifier, the load current flows A. only for the positive half cycle of the input signal B. only for the negative half cycle of the input signal C. for full cycle D. for less than fourth cycle Answer: A
18. For a NPN bipolar transistor, what is the main stream of current in the base region? A. Drift of holes B. Diffusion of holes C. Drift of electrons D. Diffusion of electrons Answer: B
19. Assertion (A): A VMOS can handle much larger current than other field effect transistors. Reason (R): In a VMOS the conducting channel is very narrow. A. Both A and R are true and R is correct explanation of A B. Both A and R are true but R is not a correct explanation of A C. A is true but R is false D. A is false but R is true Answer: C
20. In monolithic ICs, all the components are fabricated by A. diffusion process B. oxidation C. evaporation D. none Answer: A
21. Which one of the following is not a characteristic of a ferroelectric material? A. High dielectric constant B. No hysteresis C. Ferroelectric characteristic only above the curie point D. Electric dipole moment Answer: C
22. In the sale of diamonds the unit of weight is carat. One carat is equal to A. 100 mg B. 150 mg C. 200 mg D. 500 mg Answer: C
23. Assertion (A): A JFET can be used as a current source. Reason (R): In beyond pinch off region the current in JFET is nearly constant. A. Both A and R are true and R is correct explanation of A B. Both A and R are true but R is not a correct explanation of A C. A is true but R is false D. A is false but R is true Answer: A
24. Permalloy is A. a variety of stainless steel B. a polymer C. a conon-ferrous alloy used in aircraft industry D. a nickel an iron alloy having high permeability Answer: D
25. Which of the following could be the maximum current rating of junction diode by 126? A. 1 A B. 10 A C. 20 A D. 100 A Answer: A
26. Each cell of a static Random Access memory contains A. 6 MOS transistor B. 4 MOS transistor, 2 capacitor C. 2 MOS transistor, 4 capacitor D. 1 MOS transistor and 1 capacitor Answer: A
27. An electron in the conduction band A. has higher energy than the electron in the valence band B. has lower energy than the electron in the valence band C. loses its charge easily D. jumps to the top of the crystal Answer: A
28. The dynamic resistance of a forward biased p-n diode A. varies inversely with current B. varies directly with current C. is constant D. is either constant or varies directly with current Answer: A
29. A thermistor is a A. thermocouple B. thermometer C. miniature resistance D. heat sensitive explosive Answer: C
30. When diodes are connected in series to increase voltage rating the peak inverse voltage per junction A. should not exceed half the breakdown voltage B. should not exceed the breakdown voltage C. should not exceed one third the breakdown voltage D. may be equal to or less than breakdown voltage Answer: C
31. Hall effect is observed in a specimen when it is carrying current and is placed in a magnetic field. The resultant electric field inside the specimen is A. normal to both current and magnetic field B. in the direction of current C. antiparallel to magnetic field D. in arbitrary direction Answer: A
32. In an ideal diode there is no breakdown, no ______current, and no forward ______drop. A. reverse, voltage B. forward, current C. forward, voltage D. reverse, current Answer: A
33. Silicon is not suitable for fabrication of light emitting diodes because it is A. an indirect band gap semiconductor B. direct band gap semiconductor C. wideband gap semiconductor D. narrowband gap semiconductor Answer: A
34. MOSFET can be used as a A. current controlled capacitor B. voltage controlled capacitor C. current controlled inductor D. voltage controlled inductor Answer: B
35. Power diodes are generally A. silicon diodes B. germanium diodes C. either of the above D. none of the above Answer: A
36. The depletion layer width of Junction A. decreases with light doping B. is independent of applied voltage C. is increased under reverse bias D. increases with heavy doping Answer: C
37. Forbidden energy gap in germanium at 0 K is about A. 10 eV B. 5 eV C. 2 eV D. 0.78 eV Answer: D
38. Light dependent resistors are A. highly doped semiconductor B. intrinsic semiconductor C. lightly doped semiconductor D. either (a) or (c) Answer: C
39. Fermi level is the amount of energy in which A. a hole can have at room temperature B. an electron can have at room temperature C. must be given to an electron move to conduction band D. none of the above Answer: C
40. When avalanche breakdown occurs covalent bonds are not affected. A. True B. False Answer: B
41. An ideal Op-amp is an ideal A. voltage controlled current source B. voltage controlled voltage source C. current controlled current source D. current controlled voltage source Answer: B
42. Free electrons exist in A. first band B. second band C. third band D. conduction band Answer: D
43. As compared to bipolar junction transistor, a FET A. is less noisy B. has better thermal stability C. has higher input resistance D. all of the above Answer: D
44. For a P-N diode, the number of minority carriers crossing the junction depends on A. forward bias voltage B. potential barrier C. rate of thermal generation of electron hole pairs D. none of the above Answer: C
45. Which variety of copper has the best conductivity? A. Pure annealed copper B. Hard drawn copper C. Induction hardened copper D. Copper containing traces of silicon Answer: A
46. The output, V-I characteristics of an Enhancement type MOSFET has A. only an ohmic region B. only a saturation region C. an ohmic region at low voltage value followed by a saturation region at higher voltages D. an ohmic region at large voltage values preceded by a saturation region at lower voltages Answer: C
47. Piezoelectric quartz crystal resonators find application where A. signal amplification is required B. rectification of the signal is required C. signal frequency control is required D. modulation of signal is required Answer: B
48. The forbidden energy gap between the valence band and conduction band will be least in case of A. metals B. semiconductors C. insulators D. all of the above Answer: A
49. If too large current passes through the diode A. all electrons will leave B. all holes will freeze C. excessive heat may damage the diode D. diode will emit light Answer: C
50. In a bipolar transistor, the emitter base junction has A. forward bias B. reverse bias C. zero bias D. zero or reverse bias Answer: A
ELECTROMAGNETIC FIELD THEORY 1. When a wave is incident from the more dense into a less dense medium at an angle equal to or exceeding the critical angle, the wave suffers total internal ______. A. reflection B. refraction C. transmission D. none of the above Answer: B
2. Radiation intensity in a given direction is the A. energy radiated per square metre B. power radiated per square metre C. power radiated per unit solid angle in that direction D. none of the above Answer: C
3. Parabolic and lens antenna used at A. microwave frequency B. medium frequency C. low frequency D. high frequency Answer: A
4. Which of the following statement regarding waveguides is incorrect? A. At waveguide can be coupled to a coaxial cable B. At frequencies below the cut off value the wave progresses across the waveguide after total reflections C. Waveguides are usually air filled hollow conducting metallic tubes for transmitting UHF and microwaves D. Waveguides can handle large power at UHF and microwaves Answer: A
5. The potential that appears at a point in space due to the current which caused it is called potential A. accelerating B. retardation C. oscillating D. lagging the current Answer: B
6. The useful magnetic flux obtainable from any closed surface is A. unity B. constant C. both (a) and (b) D. none of the above Answer: D
7. It is best to use for coupling a coaxial line to a parallel wire transmission line. A. directional Coupler B. balun C. slotted line D. tee Answer: B
8. In H-plane metal plate lens the travelling wave front is A. totally retarded B. retarded C. accelerated D. neither accelerated nor retarded Answer: B
9. MUF is depend upon A. electron density of the ionospheric layer B. 11 year sun spot cycle C. received frequency by receiver D. height of ionospheric layer Answer: C
10. In case of antenna the ratio of the power radiated in the desired direction to the power radiated in the opposite direction is known as A. transmission efficiency B. front to back ratio C. loss coefficient D. none of the above Answer: B
11. The radiation pattern of Hertzian dipole in the plane perpendicular to dipole is a A. null B. circle C. figure of eight D. none of the above Answer: C
12. The transmitting antennas for lower frequencies (below 500 kHz) are generally A. vertical grounded wire type B. horizontal suspended wire type C. parabolic reflector type D. any of the above Answer: A
13. A satellite that simply reflect back the signals from one region of the earth to the other region is known as A. orbiting satellite B. geostationary satellite C. active satellite D. passive satellite Answer: D
14. The critical frequency of ‘F’ layer is greater than 30 MHz. A. True B. False Answer: B
15. Which of the following will increase the antenna radiation efficiency? A. Use of larger section of conductor B. Providing insulation on conductor C. Top loading of antenna D. Any of the above Answer: C
16. A waveguide operated below cut off frequency can be used as A. phase shifter B. an attenuator C. an isolator D. none Answer: B
17. Which of the following impedance inversion is obtained? A. Short-circuited stub B. A quarter wave line C. Balun transformer D. A half wave line Answer: B
18. In case of surface waves the field strength at a point is directly proportional to A. antenna height B. wave frequency C. current of the antenna D. distance of the point from the antenna Answer: D
19. Which of the following statement is false? A. Television signals are propagated as ground waves B. Surface waves can propagate on piezoelectric substrates C. The skip distance is the maximum distance upto which ionospheric reflection is possible D. Tropospheric scatter propagation is always subjects to fading Answer: C
20. Tropospheric scatter is used with frequencies in the A. HF B. VHF C. UHF D. VLF Answer: C
21. A Yagi antenna has a driven antenna A. only B. with a reflector C. with one or more directors D. with a reflector and one or more directors Answer: D
22. The minimum height of outer atmosphere is A. 100 km B. 150 km C. 200 km D. 400 km Answer: D
23. A square corner reflector is used in A. radio astronomy B. tv broadcast C. point to point communication D. all of the above Answer: D
24. The wave in wave guide has A. group velocity inversely proportional to wavelength B. larger frequency than in the free space C. diminishing wavelength than in the free space D. larger wavelength than in the free space Answer: D
25. The power gain of a half-wave dipole with respect to an isotropic radiator is A. 2.15 db B. 3 db C. 4.15 db D. 6 db Answer: A
26. In an impedance smith chart, a clockwise movement along a constant resistance circle gives rise to A. decrease in the value of reactance B. an increase in the value of reactance C. no change in the reactance value D. no change in the impedance value Answer: B
27. When the phase velocity of an EM wave depends on frequency in any medium the phenomenon is called A. scattering B. polarisation C. absorption D. dispersion Answer: B
28. The main disadvantage of the two-hole directional coupler is A. poor directivity B. narrow bandwidth C. high standing wave ratio D. low directional coupling Answer: B
29. The radiation pattern of a parabola antenna is A. omnidirectional B. a figure of directional C. highly directional D. none of the above Answer: C
30. In microwave communication links, when fading due to rain attenuation occurs then technique adopted for solving the problem would include A. antenna replacement and feed correction B. amplitude timing and phase correction C. polarization shifting and code diversity D. path diversity and frequency diversity Answer: D
31. Due to which of the following reasons a lightning conductor on top of a building is made into a pointed spike? A. Dust particles may not accumulate B. Charge per unit area becomes very high for lightening to discharge C. Rain drops may not collect D. None of the above Answer: B
32. The virtual height of an ionospheric layer is ______true height A. equal to B. less than C. higher than D. no relation Answer: C
33. The divergence of a vector is a scalar, while the curl of a vector is another A. scalar B. vector C. unit vector D. none of the above Answer: B
34. An open wire transmission line having a characteristic impedance of 600 ohms is terminated by a resistive load of 900 O. The standing wave ratio will be A. 1.5 B. 2.5 C. 3.5 D. 4.5 Answer: A
35. The skip distance is the maximum distance upto which ionospheric reflection is possible. A. True B. False Answer: B
36. Which antenna is a wideband antenna? A. Hertz antenna B. Marconi antenna C. Folded dipole D. None of the above Answer: C
37. The radiation pattern of loop antenna is A. circle B. semicircle C. elliptical D. cardoid or Limacon Answer: D
38. Tropospheric scatter propagation is not subject to any fading. A. True B. False Answer: B
39. The attenuation in waveguide above to cut off frequency A. very high B. very low C. zero D. infinite Answer: B
40. When a current carrying conductor is brought into magnetic field, the force that moves the conductor depends upon A. the value of current B. the weight of the conductor C. the direction of the conductor D. none of the above Answer: A
41. A square corner reflector is used in which of the following? A. TV broadcast B. Point-to-point communication C. Radio astronomy D. All of the above Answer: D
42. According to maximum power transfer theorem, the maximum power is absorbed by one network from another network when A. the impedance of one of the networks is half that of the other B. the impedance of one is the complex conjugate of the other C. the impedance of one is equal to that of the other D. none of the above Answer: B
43. The static electric field in a conductor is A. zero B. unity C. infinity D. none of the above Answer: A
44. In a perfect conductor the incident and reflected wave combine to produce A. a stronger incident wave B. a stronger reflected wave C. a standing wave which is not progressing D. none of the above Answer: C
45. MUF is highest in periods of greatest sunspot activity. A. True B. False Answer: A
46. Which of the following is multiband HF receiving antenna? A. Square loop B. Log-periodic C. Conical horn D. Folded dipole Answer: B
47. A rectangular waveguide is a A. rectangular conducting wire to propagate electromagnetic waves B. hollow rectangular walled room carrying electromagnetic wave C. hollow rectangular conducting tube through which electromagnetic waves can be propagated D. tube antenna to transmit and receive electromagnetic waves Answer: C
48. If a and b are the dimensions of waveguide then A. a = 3b B. a = 2b C. a = b D. a = b/4 Answer: B
49. The frequency range for satellite communication is A. 3 to 30 kHz B. 300 to 3000 kHz C. 3000 to 30000 MHz D. 30000 to 300000 MHz Answer: C
50. A loop antenna is a commonly used for A. radar B. direction finding C. satellite communication D. all of the above Answer: B
COMMUNICATION SYSTEMS 1. A cordless telephone using separate frequencies for transmission in base and portable units is known as A. duplex arrangement B. half duplex arrangement C. either (a) or (b) D. neither (a) nor (b) Answer: Option A
2. For attenuation of high frequencies we should use A. shunt capacitance B. series capacitance C. inductance D. resistance Answer: Option A
3. A modem is classified as low speed if data rate handled is A. upto 100 bps B. upto 250 bps C. upto 400 bps D. upto 600 bps Answer: Option D
4. VSB modulation is preferred in TV because A. it reduces the bandwidth requirement to half B. it avoids phase distortion at low frequencies C. it results in better reception D. none of the above Answer: Option A
5. A woofer should be fed from the input through a A. low pass filter B. high pass filter C. band pass filter D. band stop filter Answer: Option A
6. Which of the following is an indirect way of generating FM? A. Armstrong modulator B. Varactor diode modulator C. Reactance FET modulator D. Reactance bipolar transistor Answer: Option A
7. When the length of antenna is a whole wavelength A. the radiation at right angles is zero B. the radiation at right angles is maximum C. the radiation is zero in all directions D. the radiation is maximum in all directions Answer: Option A
8. Circular polarization A. is useful in reducing depolarization effect on received wave B. involves critical alignment of transmitting and receiving antenna C. is useful in discrimination between reception of adjacent beams D. none of the above Answer: Option A
9. An FM radio receiver which is tuned to a 91.6 MHz broadcast station may receive an image frequency of ______MHz. A. 102.3 B. 113 C. 70.2 D. 80.9 Answer: Option B
10. For telegraphy the most commonly used modulation system is A. FSK B. two tone modulation C. PCM D. single tone modulation Answer: Option A
11. Commercial Frequency deviation of FM is A. 70 kHz B. 75 kHz C. 80 kHz D. 65 kHz Answer: Option B
12. The colour of an object is decided by A. the reflected colour B. the wavelength transmitted through it C. reflected colour for opaque object and wavelength transmitted through it for transparent objects D. none of the above Answer: Option C
13. In Pulse Code Modulation system A. large bandwidth is required B. quantising noise can be overcome by companding C. quantising noise can be reduced by decreasing the number of standard levels D. suffers from the disadvantage of its incompatibly with TDM Answer: Option A
14. If output power of a radio receiver is doubled, its volume is increased by ______dB. A. 2 B. 3 C. 1 D. -3 Answer: Option B
15. Which of the following statements is correct? A. Convex lens has positive focal power and concave lens have negative focal power B. Convex lens has negative focal power and concave lens have positive focal power C. All lens have positive focal power D. All lens have negative focal power Answer: Option A
16. In Modulation, “carrier” is A. resultant wave B. speech voltage to be transmitted C. voltage with constant frequency, phase or amplitude D. voltage for which frequency, phase or amplitude is varied Answer: Option D
17. To eliminate ghosts in the picture A. use a longer transmission line B. connect a booster C. change the antenna orientation of location D. twist the transmission line Answer: Option C
18. The frequency range of 300 kHz to 3000 kHz is known as A. low frequency B. medium frequency C. high frequency D. very high frequency Answer: Option B
19. Which of the following does not cause losses in optical fibre cables? A. Stepped index operation B. Impurities C. Microbending D. Attenuation in glass Answer: Option A
20. For a low level AM system, the amplifiers modulated stage must be A. linear devices B. harmonic devices C. class C amplifiers D. non-linear devices Answer: Option A
21. Assertion (A): In FM the frequency of the carrier is varied by the modulating voltage Reason (R): FM and PM are two forms of angle modulation. A. Both A and R are correct and R is correct explanation of A B. Both A and R are correct but R is not correct explanation of A C. A is correct but R is wrong D. A is wrong but R is correct Answer: Option B
22. A telephone channel requires a bandwidth of about A. 1 kHz B. 3 kHz C. 10 kHz D. 50 kHz Answer: Option B
23. For a given carrier wave, maximum undistorted power is transmitted when value of modulation is A. 1 B. 0.8 C. 0.5 D. 0 Answer: Option A
24. As per Shannon-Hartley theorem, a noise less Gaussian channel has A. zero capacity B. infinite capacity C. small capacity D. none of the above Answer: Option B
25. DVD uses A. Laser beam for both recording and playback B. Laser beam for recording and video head for playback C. Video head for recording and laser beam for playback D. None of the above Answer: Option A
26. Fourier analysis indicate that a square wave can be represented as A. a fundamental sine wave and odd harmonics B. a fundamental sine wave and even harmonics C. a fundamental sine wave and harmonics D. fundamental and subharmonic sine waves Answer: Option A
27. FM transmitting and receiving equipment as compared to AM equipment is A. costly B. cheaper C. almost equally costly D. none of the above Answer: Option A
28. An audio signal (say from 50 Hz to 10000 Hz) is frequency translated by a carrier having a frequency of 106 Hz. The values of initial (without frequency translation) and final (after frequency translation) fractional change in frequency from one band edge to the other are A. 200 and 1.01 B. 200 and 10.01 C. 200 and 100.1 D. 200 and 200 Answer: Option A
29. If in a broadcasting studio, a 1000 kHz carrier is modulated by an audio signal of frequency range 100-5000 kHz, the width of channel is ______kHz. A. 5 B. 4.9 C. 995 D. 10 Answer: Option D
30. Which one of the following is analog? A. PCM B. PWM C. Delta modulation D. Differential PCM Answer: Option B
31. The disadvantage of FM over AM is that A. high output power is needed B. high modulating power is needed C. noise is very high for high frequency D. large bandwidth is required Answer: Option D
32. Which of the following is a digital modulation technique? A. PCM B. PSK C. DM D. All Answer: Option B
33. Which of the following is used to generate PDM? A. Free running multi-vibrator B. Monostable multi-vibrator C. JK flip-flop D. Schmitt trigger Answer: Option B
34. SSB can be generated by A. filter method B. phase cancellation method C. good attenuation characteristics D. all of the above Answer: Option D
35. A zero mean white Gaussian noise is passed through an ideal low pass filter of bandwidth 10 kHz. The output of the samples so obtained would be A. correlated B. statistically independent C. uncorrelated D. orthogonal Answer: Option B
36. What is the purpose of peak clipper circuits in radio transmitters? A. To prevent overmodulation B. To reduce bandwidth C. To increase bandwidth D. To regulate oscillator I/P voltage Answer: Option A
37. In case of low level amplitude modulation system, the amplifiers following the modulated stage must be A. class C amplifiers B. linear devices C. non-linear devices D. harmonic devices Answer: Option B
38. Under ordinary circumstances, impulse noise can be reduced in A. FM only B. AM only C. both AM and FM D. none of the above Answer: Option A
39. In case of frequency modulation, modulating voltage remains constant if the modulating frequency is lowered, then A. amplitude of distant sidebands decreases B. amplitude of distant sidebands increases C. amplitude of distant sidebands remains constant D. amplitude of distant sidebands first increases, then decreases Answer: Option B
40. If sampling is done at the rate of 10 kHz. The bandwidth required is A. 35 kHz B. 70 kHz C. 10 kHz D. 1280 kHz Answer: Option A
41. It is found that a ship to ship communication suffers from fading. This can be avoided by using A. space diversity B. frequency diversity C. broad band antenna D. directional antenna Answer: Option B
42. Skip distance depends on time of day and angle of incidence. A. True B. False Answer: Option A
43. In practical commercial FM system, channel bandwidth is A. 150 kHz B. 100 kHz C. 88 MHz D. 108 MHz Answer: Option A
44. In EM waves, polarization A. is always vertical in an isotropic medium B. is caused by reflection C. is due to transverse nature of waves D. results from longitudinal nature of waves Answer: Option C
45. The maximum power output of a standard A earth station over the total band allocated to satellite communication is about A. 0.5 kW B. 8 kW C. 20 kW D. 50 kW Answer: Option A
46. PAM stands for A. Pulse Analogue Modulation B. Phase Analogue Modulation C. Pulse Amplitude Modulation D. Phase Amplitude Modulation Answer: Option C
47. The characteristic impedance of a twin wire feeder used for TV signals is about A. 1000 ohm B. 500 ohm C. 300 ohm D. 100 ohm Answer: Option C
48. In a FM receiver, amplitude limiter A. amplifiers low frequency signals B. reduces the amplitude of signals C. eliminates any change in amplitude of received FM signals D. none of the above Answer: Option C
49. A buffer amplifier is A. a double-tuned amplifier B. a high gain D.C. amplifier C. a cathode follower stage D. none of the above Answer: Option B
50. Leak type bias is used in plate modulated class C amplifier to A. increase the bandwidth B. prevent over modulation C. prevent excessive grid current D. prevent tuned circuit damping Answer: Option C
51. The direction of rotation of a CD is A. clockwise B. anticlockwise C. clockwise or anticlockwise depending on frequency of data stored D. mostly anticlockwise but sometimes clockwise Answer: Option B
52. One of the advantages of base modulation over collector modulation of a transistor class C amplifier is A. improved efficiency B. better linearity C. high power output per transistor D. the lower modulating power requirement Answer: Option D
53. Full duplex operation-permits transmission in both directions at the same time. A. True B. False Answer: Option A
54. In a TV receiver antenna the length of reflector rod A. is the same as that of dipole B. is less than that of dipole C. is more than that of dipole D. may be equal, more or less than that of dipole Answer: Option C
55. The modulation index of an FM is changed from 0 to 1. How does the transmitted power change? A. Gets halved B. Gets doubled C. Gets increased by 50 percent D. Remains unchanged Answer: Option C
56. For AM receivers the standard IF frequency is A. 106 kHz B. 455 kHz C. 1.07 MHz D. 10.7 MHz Answer: Option B
57. For a plate-modulated class C amplifier the plate supply voltage is E. The maximum plate cathode voltage could be almost high as A. 2E B. 3E C. 4E D. 6E Answer: Option C
58. In TV systems, equalising pulses are sent during A. horizontal blanking B. vertical blanking C. serrations D. horizontal retrace Answer: Option A
59. A three stage telephone switching structure is to have 128 input and 128 output terminals. There are 16 first stage and 16 third stage matrices. To avoid blocking the number of intermediate paths required is A. 16 B. 15 C. 8 D. 1 Answer: Option B
60. The main function of a balanced modulator is to A. produce balanced modulation of a carrier wave B. produce 100% modulation C. suppress carrier signal in order to create a single-sideband or double sideband D. limit noise picked by a receiver Answer: Option B AUTOMATIC CONTROL SYSTEMS 1. Which of the following can be used as a rotating amplifier in a control system? 1. Amplidyne 2. Separately excited dc generator 3. Synchro 4. Self excited dc generator Select the answer from the following codes: A. 3 and 4 B. 1 and 2 C. 1, 2 and 3 D. all Answer: B
2. A lead compensator A. speeds up the transient response B. increases the stability margin C. increases the stability margin and speeds up the transient-response. D. none of the above. Answer: C
3. The effect of adding poles and zeros can be determined quickly by A. Nichols chart B. Nyquist plot C. Bode plot D. Root locus Answer: C
4. In force current analogue, mechanical mobility is analogous to A. impedance Z B. admittance Y C. reactance X D. conductance G Answer: A
5. If any term in the first column of a Routh array becomes zero, then A. Routh criterion cannot be used to determine stability B. Routh criterion can be used by substituting a small positive number for zero and completing the array C. Routh criterion can be used by substituting a big positive number for zero and completing the array D. Routh criterion can be used by substituting a small negative number for zero and completing the array Answer: B
6. Which of the following features is not associated with Nichols chart? A. (0 dB, -180°) point on Nichols chart represent critical Point (-1, 0) B. It is symmetric about -180° C. M loci are centred about (0 dB, -180°) point D. The frequency at intersection of G(j?) locus and M = +3 dB locus gives bandwidth of closed loop system Answer: D
7. A system is highly oscillatory if A. gain margin is high B. gain margin is close to 1 C. gain margin is close to 1 or phase margin is zero D. gain margin is high and phase margin is 180° Answer: C
8. Which of the following is correct? A. Speed torque characteristics of permanent magnet dc servomotor is more flat than that of wound field dc servomotor B. Speed torque characteristics of wound field dc servo- motor is more flat than that of permanent magnet dc servo motor C. Speed torque characteristics of wound field and permanent magnet dc servomotor are equally flat D. None of the above Answer: A
9. A conditionally stable system is stable for the value of gain between two critical values. It is unstable if A. the gain is increased beyond upper critical value B. the gain is decreased below lower critical value C. both (a) and (b) D. none of the above Answer: C
10. Transport lag usually exists in A. thermal systems B. hydraulic systems and thermal systems C. pneumatic systems D. thermal, hydraulic and pneumatic systems Answer: D
11. Which of the following can act as error detecting devices 1. a pair of potentiometers 2. a pair of synchros 3. a differential transformer 4. a metadyne 5. a control transformer Select the answer using the following codes: A. 1, 2, 5 B. 2, 3, 4, 5 C. 1, 3, 4, 5 D. 1, 2, 3, 4 Answer: A
12. For type 1 system the velocity lag error is A. inversely proportional to bandwidth of system B. directly proportional to gain constant C. inversely proportional to gain constant D. independent of gain constant Answer: C
13. Nyquist stability criterion uses open loop frequency response characteristics. A. True B. False Answer: A
14. Integral control action A. removes offset B. may lead to oscillatory response C. both (a) and (b) D. neither (a) nor (b) Answer: C
15. The sensor generally used in incremental optical encoder is A. LED B. LCD C. photodiode D. either (a) or (b) Answer: C
16. Robotic manipulator arms mostly use A. hydraulic actuator B. pneumatic actuator C. electric motor actuator D. none of the above Answer: C
17. Lag compensation permits a high gain at low frequencies. A. True B. False Answer: A
18. If the poles lie in second quadrant, damping ratio is A. 1 B. less than 1 C. zero D. more than 1 Answer: B
19. Which of the following is used to obtain output position in a position control system? A. Strain gauge B. Load cell C. Synchro D. Thermistor Answer: B
20. DC tachogenerator can be used in A. speed control system B. position control system C. both (a) and (b) D. neither (a) nor (b) Answer: C
21. For a stable system having two or more gain crossover frequencies the phase margin is measured at the highest crossover frequency. A. True B. False Answer: A
22. In a two phasor servomotor, the direction of rotation of the rotating field depends on A. magnitudes of voltages applied to the two stator windings B. phase relation of voltages applied to the two stator windings C. both magnitude and phase relationship of voltages applied to the two stator windings D. none of the above Answer: B
23. Gain margin and phase margin can be determined from Bode plots as well as Nyquist plot. A. True B. False Answer: A
24. The permanent magnet field system of brushless dc servo- motor is generally on A. stator B. rotor C. partly on stator and partly on rotor D. either (a) or (b) Answer: B
25. For any transfer function, the constant phase angle loci are A. a family of circles B. a family of straight lines C. either (a) or (b) D. neither (a) nor (b) Answer: A
26. In force current analogy, displacement x is analogous to A. charge B. magnetic flux linkage C. electrostatic energy D. voltage Answer: B
27. In Bode plots the frequency at which two asymptotes meet is called corner frequency. A. True B. False Answer: A
28. In Bode plots, frequency is plotted on log scale. A. True B. False Answer: A
29. Nichol’s chart is symmetric about – 180° axis. A. True B. False Answer: A
30. If poles lie in first quadrant, damping ratio is A. 1 B. more than 1 C. less than 1 D. zero Answer: C
31. Which control action can never be used alone? A. Proportional B. Derivative C. Integral D. Both (b) and (c) Answer: B
32. In a simple on-off controller with differential gap, the magnitude of differential gap determines A. the level of accuracy B. the life of controller C. both (a) and (b) D. neither (a) nor (b) Answer: C
33. Which dc servomotor requires strongest permanent magnet? A. Slotted armature B. Surface wound armature C. Surface wound with stationary rotor D. Either (a) or (b) Answer: C
34. Nichols chart consists of A. constant magnitude loci B. constant phase angle loci C. magnitude and phase angle loci in log-magnitude versus phase diagram D. none of the above Answer: C
35. Consider the following statements about root locus 1.The intersection of root locus branches with the imaginary axis can be determined by the use of Routh criterion 2.Segments of real axis having an odd number of real axis open loop poles plus zeros to their right are not parts of root locus 3.The number of root locus branches terminating on infinity is always zero Which of the above statements are correct? A. 1, 2 and 3 B. 1 and 2 only C. 1 only D. 2 and 3 only Answer: B
36. The poles with greater displacement from the real axis correspond to A. higher frequencies of oscillations B. stable response C. lower frequencies of oscillations D. unbounded output Answer: A
37. Which of the following is open loop system? A. Wind screen wiper B. Aqualing C. Respiratory system of animal D. System for controlling antirocket missiles Answer: A
38. Consider the following statements 1. The effect of feedback is to reduce system error 2. Feedback increases the system gain at one frequency but reduces the system gain as another frequency 3. Feedback can cause an originally stable system to become unstable Which of the above statements are correct? A. 1, 2, 3 B. 1, 2 C. 2, 3 D. 1, 3 Answer: D
39. M circles are symmetrical with respect to A. real and imaginary axis B. M = 1 straight line and real axis C. M = 1 straight line and imaginary axis D. M = 1 straight line Answer: B
40. A lag compensator A. speeds up the transient response of the system B. improves steady state behaviour of the system C. improves steady state behaviour and speeds up the transient response of the system D. improves steady state behaviour and preserves the transient response of the system Answer: D
41. In root locus analysis the breakaway and break in points A. lie on the real axis B. either lie on the real axis or occur in complex conjugate pairs C. always occur in complex conjugate pairs D. none of the above Answer: B
42. In control systems the output of sensor usually, is A. analog electrical signal B. digital electrical signal C. mechanical signal D. analog or digital electrical signal Answer: D
43. Magnetic amplifier is used for A. voltage amplification B. power amplification C. current amplification D. frequency amplification Answer: B
44. Temperature is analogous to A. voltage B. flux C. charge D. none of the above Answer: A
45. The relative stability of a system is given by A. gain margin alone B. phase margin alone C. both phase and gain margins D. either (a) or (b) Answer: C
46. Bandwidth is proportional to speed of response. A. True B. False Answer: A
47. The complicated shapes in the polar plots are only due to time constants in the numerator of transfer functions. A. True B. False Answer: A
48. The distance of poles from origin depends on A. undamped natural frequency B. damping ratio C. both (a) and (b) D. neither (a) nor (b) Answer: A
49. In the field controlled motor the entire damping comes from A. armature resistance B. back emf C. motor friction and load D. field resistance Answer: C
50. The addition of a pole to the open loop transfer function pulls the root locus A. to the right B. to the left and making the system more stable C. towards right or left depending on the position of new pole D. none of the above Answer: A OP-AMP 1. A differential amplifier …………….. 1. Is a part of an Op-amp 2. Has one input and one output 3. Has two outputs 4. Answers (1) and (2) Ans : 4
2. When a differential amplifier is operated single-ended, ………… 1. The output is grounded 2. One input is grounded and signal is applied to the other 3. Both inputs are connected together 4. The output is not inverted Ans : 2
3. In differential-mode……………. 1. Opposite polarity signals are applied to the inputs 2. The gain is one 3. The outputs are of different amplitudes 4. Only one supply voltage is used Ans : 1
4. In the common mode…………… 1. Both inputs are grounded 2. The outputs are connected together 3. An identical signal appears on both the inputs 4. The output signal are in Ans : 3
5. The common mode gain is 1. Very high 2. Very low 3. Always unity 4. Unpredictable Ans : 2
6. The differential gain is ……… 1. Very high 2. Very low 3. Dependent on input voltage 4. About 100 Ans : 1
7. If ADM = 3500 and ACM = 0.35, the CMRR is ………. 1. 1225 2. 10,000 3. 80 dB 4. Answers (1) and (3) Ans : 4
8. With zero volts on both inputs, an OP 1. Equal to the positive supply voltage 2. Equal to the negative supply voltage 3. Equal to zero 4. Equal to CMRR Ans : 3
9. Of the values listed, the most realistic value for open loop voltage gain of an OP amp is ……….. 1.1 2. 2000 3. 80 dB 4. 100,000 Ans : 4
10. A certain OP-amp has bias currents of 50 µA. The input offset current is …….. 1. 700 nA 2. 99.3 µA 3. 49.7 µA 4. None of these Ans : 1
11. The output of a particular Op-amp increases 8V in 12µs. The slew rate is ……. 1. 90 V/µs 2. 0.67 V/µs 3. 1.5 V/µs 4. None of these Ans : 2
12. For an Op-amp with negative feedback, the output is ……. 1. Equal to the input 2. Increased 3. Fed back to the inverting input 4. Fed back to the non-inverting input Ans : 3
13. The use of negative feedback ……… 1. Reduces the voltage gain of an Op-amp 2. Makes the Op-amp oscillate 3. Makes linear operation possible 4. Answers (1) and (2) Ans : 4
14. Negative feedback ……….. 1. Increases the input and output impedances 2. Increases the input impedance and bandwidth 3. Decreases the output impedance and bandwidth 4. Does not affect impedance or bandwidth Ans : 2
15. A certain noninverting amplifier has Ri of 1 kO and Rf of 100 kO. The closed-loop voltage gain is ……… 1. 100,000 2. 1000 3. 101 4. 100 Ans : 3
16. If the feedback resistor in Q15 (above question) is open, the voltage gain ……. 1. Increases 2. Decreases 3. Is not affected 4. Depends on Ri Ans : 1
17. A certain inverting amplifier has a closed-loop voltage gain of 25. The Op-amp has an open- loop voltage gain of 100,000. If an Op-amp with an open-loop voltage gain of 200,000 is substituted in the arrangement, the closed-loop gain …….. 1. Doubles 2. Drops to 12.5 3. Remains at 25 4. increases slightly Ans : 3
18. A voltage follower ………. 1. Has a voltage gain of 1 2. Is noninverting 3. Has no feedback resistor 4. Has all of these Ans : 4
19. The Op-amp can amplify 1. a.c. signals only 2. d.c. signals only 3. Both a.c. and d.c. signals 4. Neither d.c. nor a.c. signals Ans : 3
20. The input offset current equals the ………. 1. Difference between two base currents 2. Average of two base currents 3. Collector current divided by current gain 4. None of these Ans : 1
21. The tail current of a differential amplifier is ……. 1. Half of either collector current 2. Equal to either collector current 3. two times either collector current 4. Equal to the difference in base currents Ans : 3
22. The node voltage at the top of the til resistor is closes to ………. 1. Collector supply voltage 2. Zero 3. Emitter supply voltage 4. Tail current times base resistance Ans : 2
23. The tail current in a differential amplifier equals ……. 1. Difference between two emitter currents 2. Sum of two emitter currents 3. Collector current divided by current gain 4. Collector voltage divided by collector resistance Ans : 2
24. The differential voltage gain of a differential amplifier is equal to RC divided by ……. 1. r’e 2. r’e/2 3. 2r’e 4. RE Ans : 3
25. The input impedance of a differential amplifier equals r’e times …… 1. ß 2. RE 3. RC 4. 2ß Ans : 4
26. A common-mode signal is applied to ………. 1. The noninverting input 2. The inverting input 3. Both inputs 4. Top of the tail resistor Ans : 3
27. The common-mode voltage gain is ……… 1. Smaller than differentail voltage gain 2. Equal to differential voltage gain 3. Greater than differential voltage gain 4. None of the above Ans : 1
28. The input stage of an Op-amp is usually a ………. 1. Differential amplifier 2. Class B push-pull amplifier 3. CE amplifier 4. Swamped amplifier Ans : 1
29. The common-mode voltage gain of a differential amplifier is equal to RC divided by …….. 1. r’e 2. 2r’e 3. r’e/2 4. 2RE Ans : 4
30. Current cannot flow to ground through ……. 1. A mechanical ground 2. An a.c. ground 3. A virtual ground 4. An ordinary ground Ans : 3 TRANSISTOR AUDIO POWER AMPLIFIERS 1. The output stage of a multistage amplifier is also called …………… 1. Mixer stage 2. Power stage 3. Detector stage 4. F stage Ans : 2
2. ………………. coupling is generally employed in power amplifiers 1. Transformer 2. RC 3. Direct 4. Impedance Ans : 1
3. A class A power amplifier uses ………… Two transistors Three transistors One transistor None of the above Ans : 3
4. The maximum efficiency of resistance loaded class A power amplifier is …….. 1. 5% 2. 50% 3. 30% 4. 25% Ans : 4
5. The maximum efficiency of transformer coupled class A power amplifier is ……………… 1. 30% 2. 50% 3. 80% 4. 45% Ans : 2
6. Class……. power amplifier has the highest collector efficiency 1. C 2. A 3. B 4. AB Ans : 1
7. Power amplifiers handle …………. signals compare to voltage amplifiers 1. Small 2. Very small 3. Large 4. None of the above Ans : 3
8. In class A operation, the operating point is generally located ………. of the d.c. load line. 1. At cut off point 2. At the middle 3. At saturation point 4. None of the above Ans : 2
9. Class C amplifiers are used as ……………. 1. AF amplifiers 2. Detectors 3. F. amplifiers 4. None of the above Ans : 3
10. A power amplifier has comparatively …………….. ß 1. Small 2. Large 3. Very large 4. None of the above Ans : 1
11. The maximum collector efficiency of class B operation is …………….. 1. 50% 2. 90% 3. 5% 4. 5% Ans : 4
12. A 2-transistor class B power amplifier is commonly called ……….. amplifier 1. Dual 2. Push-pull 3. Symmetrical 4. Differential Ans : 2
13. If a transistor is operated in such a way that output current flows for 60o of the input signal, then it is …………… operation 1. Class A 2. Class B 3. Class C 4. None of the above Ans : 3
14. If the zero signal dissipation of a transistor is 1W, then power rating of the transistor should be at least ………………. 1. 5 W 2. 33 W 3. 75 W 4. 1 W Ans : 4
15. When a transistor is cut off…………….. 1. Maximum voltage appears across transistor 2. Maximum current flows 3. Maximum voltage appears across load 4. None of the above Ans : 1
16. A class A power amplifier is sometimes called ………….. amplifier 1. Symmetrical 2. Single-ended 3. Reciprocating 4. Differential Ans : 2
17. Class ………….. operation gives the maximum distortion 1. A 2. B 3. C 4. AB Ans : 3
18. The output stage of a multistage amplifier usually employs ……….. 1. Push-pull amplifier 2. Preamplifier 3. Class A power amplifier 4. None of the above Ans : 1
19. The size of a power transistor is made considerably large to ………… 1. Provide easy handling 2. Dissipate heat 3. Facilitate connections 4. None of the above Ans : 2
20. Low efficiency of a power amplifier results in ………………. 1. Low forward bias 2. Less battery consumption 3. More battery consumption 4. None of the above Ans : 3
21. The driver stage usually employs…………. 1. Class A power amplifier 2. Push-pull amplifier 3. Class C amplifier 4. None of the above Ans : 1
22. If the power rating of a transistor is 1W and collector current is 100mA, then maximum allowable collector voltage is ……….. 1. 1V 2. 100V 3. 20V 4. 10V Ans : 4
23. When no signal is applied, the approximate collector efficiency of class A power amplifier is ……. 1. 10% 2. 0% 3. 25% 4. 50% Ans : 2
24. What will be the collector efficiency of a power amplifier having zero signal power dissipation of 5 watts and a.c. power output of 2 watts? 1. 20% 2. 80% 3. 40% 4. 50% Ans : 3
25. The output signal voltage and current of a power amplifier are 5V and 200 mA; the values being r.m.s. What is the power output? 1. 1 W 2. 2 W 3. 4 W 4. None of the above Ans : 1
26. The maximum a.c. power output from a class A power amplifier is 10 W. What should be the minimum power rating of the transistor used ? 1. 10 W 2. 15 W 3. 5 W 4. 20 W Ans : 4
27. For the same a.c. power output as above, what should be the minimum power rating of transistor for class B operation? 1. 10 W 2. 4 W 3. 8 W 4. None of the above Ans : 2
28. The push-pull circuit must use …………… operation 1. Class A 2. Class C 3. Class B 4. Class AB Ans : 3
29. The class B push-pull circuit can deliver 100 W of a.c. output power. What should be the minimum power rating of each transistor? 1. 20 W 2. 40 W 3. 10 W 4. 80 W Ans : 1
30. What turn ratio (Np/Ns) of transformer is required to match 4 O speaker to a transistor having an output impedance of 8000 O? 1. 2 2. 7 3. 3 4. None of the above Ans : 2
31. A transformer coupled class A power amplifier has a load of 100 O on the secondary. If the turn ratio is 10:1, what is the value of load appearing on the primary? 1. 5 kO 2. 20 kO 3. 100 kO 4. 10 kO Ans : 4
32. Power amplifiers generally use transformer coupling because transformer permits…….. 1. Cooling of the circuit 2. Impedance matching 3. Distortionless output 4. Good frequency response Ans : 2
33. Transformer coupling can be used in …………… amplifiers 1. Either power or voltage 2. Only power 3. Only voltage 4. None of the above Ans : 1
34. The output transformer used in a power amplifier is a ……………. transformer 1. 1:1 ratio 2. Step-up 3. Step-down 4. None of the above Ans : 3
35. The most important consideration in power amplifier is ……….. 1. Biasing the circuit 2. Collector efficiency 3. To keep the transformer cool 4. None of the above Ans : 2
36. An AF amplifier is shielded to ………… 1. Keep the amplifier cool 2. Protect from rusting 3. Prevent induction due to stray magnetic fields 4. None of the above Ans : 3
37. The pulsating d.c. applied to power amplifier causes …………….. 1. Burning of transistor 2. Hum in the circuit 3. Excessive forward voltage 4. None of the above Ans : 2
38. The disadvantage of impedance matching is that it …………………. 1. Gives distorted output 2. Gives low power output 3. Requires a transformer 4. None of the above Ans : 1
39. If the gain versus frequency curve of a transistor amplifier is not flat, then there is distortion. 1. Amplitude 2. Intermodulation 3. Frequency 4. None of the above Ans : 3
40. The most costly coupling is ……………… coupling 1. RC 2. Direct 3. Impedance 4. Transformer Ans : 4 MULTISTAGE TRANSISTOR AMPLIFIERS 1. A radio receiver has …………… of amplification 1. One stage 2. Two stages 3. Three stages 4. More than one stages Ans : 4
2. RC coupling is used for ………………. amplification 1. Voltage 2. Current 3. Power 4. None of the above Ans : 1
3. In an RC coupled amplifier, the voltage gain over mid-frequency range ……………. 1. Changes abruptly with frequency 2. is constant 3. Changes uniformly with frequency 4. None of the above Ans : 2
4. In obtaining the frequency response curve of an amplifier, the ………… 1. Amplifier level output is kept constant 2. Amplifier frequency is held constant 3. Generator frequency is held constant 4. Generator output level is held constant Ans : 4
5. An advantage of RC coupling scheme is the …………. 1. Good impedance matching 2. Economy 3. High efficiency 4. None of the above Ans : 2
6. The best frequency response is of ………. coupling 1. RC 2. Transformer 3. Direct 4. None of the above Ans : 3
7. Transformer coupling is used for ………….. amplification 1. Power 2. Voltage 3. Current 4. None of the above Ans : 1
8. In an RC coupling scheme, the coupling capacitor CC must be large enough 1. To pass d.c. between the stages 2. Not to attenuate the low frequencies 3. To dissipate high power 4. None of the above Ans : 2
9. In RC coupling, the value of coupling capacitor is about ………. 1. 100 pF 2. 0.1 µF 3. 0.01 µF 4. 10 µF Ans : 4
10. The noise factor of an ideal amplifier expressed in db is ………….. 1. 0 2. 1 3. 1 4. 10 Ans : 1
11. When a multistage amplifier is to amplify d.c. signal, then one must use …….. coupling 1. RC 2. Transformer 3. Direct 4. None of the above Ans : 3
12. ………….. coupling provides the maximum voltage gain 1. RC 2. Transformer 3. Direct 4. Impedance Ans : 2
13. In practice, voltage gain is expressed …………… 1. In db 2. In volts 3. As a number 4. None of the above Ans : 1
14. Transformer coupling provides high efficiency because ………… 1. Collector voltage is stepped up 2. c. resistance is low 3. Collector voltage is stepped down 4. None of the above Ans : 2
15. Transformer coupling is generally employed when load resistance is ……… 1. Large 2. Very large 3. Small 4. None of the above Ans : 3
16. If a three-stage amplifier has individual stage gains of 10 db, 5 db and 12 db, then total gain in db is ………. 1. 600 db 2. 24 db 3. 14 db 4. 27 db Ans : 4
17. The final stage of a multistage amplifier uses ……………… 1. RC coupling 2. Transformer coupling 3. Direct coupling 4. Impedance coupling Ans : 2
18. The ear is not sensitive to …………. 1. Frequency distortion 2. Amplitude distortion 3. Frequency as well as amplitude distortion 4. None of the above Ans : 1
19. RC coupling is not used to amplify extremely low frequencies because ……… 1. There is considerable power loss 2. There is hum in the output 3. Electrical size of coupling capacitor becomes very large 4. None of the above Ans : 3
20. In transistor amplifiers, we use ……………. transformer for impedance matching 1. Step up 2. Step down 3. Same turn ratio 4. None of the above Ans : 2
21. The lower and upper cut off frequencies are also called ………………… frequencies 1. Sideband 2. Resonant 3. Half-resonant 4. Half-power Ans : 4
22. A gain of 1,000,000 times in power is expressed by ……………. 1. 30 db 2. 60 db 3. 120 db 4. 600 db Ans : 2
23. A gain of 1000 times in voltage is expressed by ………….. 1. 60 db 2. 30 db 3. 120 db 4. 600 db Ans : 1
24. 1 db corresponds to ………….. change in power level 1. 50% 2. 35% 3. 26% 4. 22% Ans : 3
25. 1 db corresponds to …………. change in voltage or current level 1. 40% 2. 80% 3. 20% 4. 25% Ans : 1
26. The frequency response of transformer coupling is …………. 1. Good 2. Very good 3. Excellent 4. Poor Ans : 4
27. In the initial stages of a multistage amplifier, we use ……….. 1. RC coupling 2. Transformer coupling 3. Direct coupling 4. None of the above Ans : 1
28. The total gain of a multistage amplifier is less than the product of the gains of individual stages due to ………… 1. Power loss in the coupling device 2. Loading effect of the next stage 3. The use of many transistors 4. The use of many capacitors Ans : 2
29. The gain of an amplifier is expressed in db because ……….. 1. It is a simple unit 2. Calculations become easy 3. Human ear response is logarithmic 4. None of the above Ans : 3
30. If the power level of an amplifier reduces to half, the db gain will fall by ……. 1. 5 db 2. 2 db 3. 10 db 4. 3 db Ans : 4
31. A current amplification of 2000 is a gain of ……………. 1. 3 db 2. 66 db 3. 20 db 4. 200 db Ans : 2
32. An amplifier receives 0.1 W of input signal and delivers 15 W of signal power. What is the power gain in db? 1. 8 db 2. 6 db 3. 5 db 4. 4 db Ans : 1 33. The power output of an audio system is 18 W. For a person to notice an increase in the output (loudness or sound intensity) of the system, what must the output power be increased to? 1. 2 W 2. 6 W 3. 68 W 4. None of the above Ans : 3
34. The output of a microphone is rated at -52 db. The reference level is 1V under specified conditions. What is the output voltage of this microphone under the same sound conditions? 1. 5 mV 2. 2 mV 3. 8 mV 4. 5 mV Ans : 4
35. RC coupling is generally confined to low power applications because of ……… 1. Large value of coupling capacitor 2. Low efficiency 3. Large number of components 4. None of the above Ans : 2
36. The number of stages that can be directly coupled is limited because …….. 1. Changes in temperature cause thermal instability 2. Circuit becomes heavy and costly 3. It becomes difficult to bias the circuit 4. None of the above Ans : 1
37. The purpose of RC or transformer coupling is to ………… 1. Block a.c. 2. Separate bias of one stage from another 3. Increase thermal stability 4. None of the above Ans : 2
38. The upper or lower cut off frequency is also called ………….. frequency 1. Resonant 2. Sideband 3. 3 db 4. None of the above Ans : 3
39. The bandwidth of a single stage amplifier is …………. that of a multistage amplifier 1. More than 2. The same as 3. Less than 4. Data insufficient Ans : 1
40. The value of emitter capacitor CE in a multistage amplifier is about …….. 1. 1 µF 2. 100 pF 3. 0.01 µF 4. 50 µF Ans : 4 SINGLE STAGE TRANSISTOR AMPLIFIERS 1. A single stage transistor amplifier contains ……………. and associated circuitry 1. Two transistors 2. One transistor 3. Three transistor 4. None of the above Ans : 2
2. The phase difference between the output and input voltages of a CE amplifier is ……………….. 1. 180o 2. 0o 3. 90o 4. 270o Ans : 1
3. It is generally desired that a transistor should have …………….. input impedance 1. Low 2. Very low 3. High 4. Very high Ans : 3
4. When an a.c. signal is applied to an amplifier, the operating point moves along ……………. 1. dc. load line 2. ac. load line 3. Both d.c. and a.c. load lines 4. None of the above Ans : 2
5. If the collector supply is 10V, then collector cut off voltage under d.c. conditions is …………. 1. 20 V 2. 5 V 3. 2 V 4. 10 V Ans : 4
6. In the zero signal conditions, a transistor sees ……………….. load 1. dc. 2. ac. 3. Both d.c. and a.c. 4. None of the above Ans : 1?
7. The input capacitor in an amplifier is the ……………….. capacitor 1. Coupling 2. Bypass 3. Leakage 4. None of the above Ans : 1
8. The point of intersection of d.c. and a.c. load lines is called …………….. 1. Saturation point 2. Cut off point 3. Operating point 4. None of the above Ans : 3
9. The slope of a.c. load line is ……………… that of d.c. load line 1. The same as 2. More than 3. Less than 4. None of the above Ans : 2
10. If a transistor amplifier draws 2mA when input voltage is 10 V, then its input impedance is ……….. 1. 20 kΩ 2. 2 kΩ 3. 10 kΩ 4. 5 kΩ Ans : 4
11. When a transistor amplifier is operating, the current in any branch is …………… 1. Sum of a.c. and d.c. 2. a.c. only 3. d.c. only 4. Difference of a.c. and d.c. Ans : 1 12. The purpose of capacitors in a transistor amplifier is to ……………… 1. Protect the transistor 2. Cool the transistor 3. Couple or bypass a.c. component 4. Provide biasing Ans : 3
13. In the d.c. equivalent circuit of a transistor amplifier, the capacitors are considered …………….. 1. Short 2. Open 3. Partially short 4. None of the above Answer : 2
14. In a CE amplifier, voltage gain = ……………. x RAC/Rin 1. α 2. (1 + α) 3. (1+ β) 4. β Ans : 4
Q15. In practice, the voltage gain of an amplifier is expressed …………….. 1. As volts 2. As a number 3. In db 4. None of the above Ans : 3
16. If the power and current gains of a transistor amplifier are 16500 and 100 respectively, then voltage gain is ……… 1. 165 2. 165 x 104 3. 100 4. None of the above Ans : 1
17. If RC and RL represent the collector resistance and load resistance respectively in a single stage transistor amplifier, then a.c. load is …….. 1. RL + RC 2. RC || RL 3. RL – RC 4. RC Ans : 2
18. In a CE amplifier, the phase difference between voltage across collector load RC and signal voltage is ……….. 1. 180o 2. 270o 3. 90o 4. 0o Ans : 4
19. In the a.c. equivalent circuit of a transistor amplifier, the capacitors are considered …………. 1. Short 2. Open 3. Partially open 4. None of the above Ans : 1
20. In a single stage transistor amplifier, RC and RL represent collector resistance and load resistance respectively. The transistor sees a d.c. load of ……….. 1. RC + RL 2. RC || RL 3. RL 4. RC Ans : 4
21. The purpose of d.c. conditions in a transistor is to ………….. 1. Reverse bias the emitter 2. Forward bias the collector 3. Set up operating point 4. None of the above Ans : 3
22. An amplifier has a power gain of 100. Its db gain is …………… 1. 10 db 2. 20 db 3. 40 db 4. None of the above Ans : 2
23. In order to get more voltage gain from a transistor amplifier, the transistor used should have ………….. 1. Thin base 2. Thin collector 3. Wide emitter 4. None of the above Ans : 1
24. The purpose of a coupling capacitor in a transistor amplifier is to ………. 1. Increase the output impedance of transistor 2. Protect the transistor 3. Pass a.c. and block d.c. 4. Provide biasing Ans : 3
25. The purpose of emitter capacitor (i.e. capacitor across RE) is to ………. 1. Avoid voltage gain drop 2. Forward bias the emitter 3. Reduce noise in the amplifier 4. None of the above Ans : 1
26. The ratio of output impedance of a CE amplifier is …………… 1. About 1 2. Low 3. High 4. Moderate Ans : 4
27. If a transistor amplifier feeds a load of low resistance (e.g. speaker), then voltage gain will be …………. 1. High 2. Very high 3. Moderate 4. Low Ans : 4
28. If the input capacitor of a transistor amplifier is short-circuited, then……… 1. Transistor will be destroyed 2. Biasing conditions will change 3. Signal will not reach the base 4. None of the above Ans : 2
29. The radio wave picked up by the receiving antenna is amplified about …….. times to have reasonable sound output 1. 1000 2. A million 3. 100 4. 10000 Ans : 2
30. A CE amplifier is also called ………….. circuit 1. Grounded emitter 2. Grounded base 3. Grounded collector 4. None of the above Ans : 1
31. The d.c. load of a transistor amplifier is generally ………….. that of a a.c. load 1. The same as 2. Less than 3. More than 4. None of the above Ans : 3
32. The value of collector load RC in a transistor amplifier is ………… the output impedance of the transistor. 1. The same as 2. Less than 3. More than 4. None of the above Ans : 2
33. A single stage transistor amplifier with collector load RC and emitter resistance RE has a d.c. load of ………. 1. RC 2. RC || RE 3. RC – RE 4. RC + RE Ans : 4
34. In transistor amplifiers, we generally use ………….. capacitors. 1. Electrolytic 2. Mica 3. Paper 4. Air Ans : 1
35. A single stage transistor amplifier with no load sees an a.c. load of …….. 1. RC + RE 2. RC 3. RC || RE 4. RC/RE Ans : 2
36. The output power of a transistor amplifier is more than the input power because the additional power is supplied by ………… 1. Transistor 2. Biasing circuit 3. Collector supply VCC 4. None of the above Ans : 3
37. A transistor converts …………… 1. dc. power into a.c. power 2. ac. power into d.c. power 3. high resistance into low resistance 4. none of the above Ans : 1?
38. A transistor amplifier has high output impedance because ……….. 1. Emitter is heavily doped 2. Collector has reverse bias 3. Collector is wider than emitter or base 4. None of the above Ans : 2
39. For highest power gain, one would use …………….. configuration 1. CC 2. CB 3. CE 4. none of the above Ans : 3
40. CC configuration is used for impedance matching because its …………….. 1. Input impedance is very high 2. Input impedance is low 3. Output impedance is very low 4. None of the above Ans : 1 TRANSISTOR BIASING
1. Transistor biasing represents ……………. conditions 1. a.c. 2. d.c. 3. both a.c. and d.c. 4. none of the above Ans : 2
2. Transistor biasing is done to keep ………… in the circuit 1. Proper direct current 2. Proper alternating current 3. The base current small 4. Collector current small Ans : 1 3. Operating point represents ………….. 1. Values of IC and VCE when signal is applied 2. The magnitude of signal 3. Zero signal values of IC and VCE 4. None of the above Ans : 3
4. If biasing is not done in an amplifier circuit, it results in …………… 1. Decrease in the base current 2. Unfaithful amplification 3. Excessive collector bias 4. None of the above Ans : 2
5. Transistor biasing is generally provided by a ……………. 1. Biasing circuit 2. Bias battery 3. Diode 4. None of the above Ans : 1
6. For faithful amplification by a transistor circuit, the value of VBE should ………. for a silicon transistor 1. Be zero 2. Be 0.01 V 3. Not fall below 0.7 V 4. Be between 0 V and 0.1 V Ans : 3
7. For proper operation of the transistor, its collector should have ………… 1. Proper forward bias 2. Proper reverse bias 3. Very small size 3. None of the above Ans : 2
8. For faithful amplification by a transistor circuit, the value of VCE should ……….. for silicon transistor 1. Not fall below 1 V 2. Be zero 3. Be 0.2 V 4. None of the above Ans : 1
9. The circuit that provides the best stabilization of operating point is ………… 1. Base resistor bias 2. Collector feedback bias 3. Potential divider bias 4. None of the above Ans : 3
10. The point of intersection of d.c. and a.c. load lines represents ………….. 1. Operating point 2. Current gain 3. Voltage gain 4. None of the above Ans : 1
11. An ideal value of stability factor is ………….. 1. 100 2. 200 3. More than 200 4. 1 Ans : 4
12. The zero signal IC is generally ……………… mA in the initial stages of a transistor amplifier 1. 4 2. 1 3. 3 4. More than 10 Ans : 2
13. If the maximum collector current due to signal alone is 3 mA, then zero signal collector current should be at least equal to ……….. 1. 6 mA 2. 3 mA 2. 3 mA 1. 1 mA Ans : 3
14. The disadvantage of base resistor method of transistor biasing is that it ………… 1. Is complicated 2. Is sensitive to changes in ß 3. Provides high stability 4. None of the above Ans : 2
15. The biasing circuit has a stability factor of 50. If due to temperature change, ICBO changes by 1 µA, then IC will change by ………… 1. 100 µA 2. 25 µA 3. 20 µA 4. 50 µA Ans : 4
16. For good stabilsation in voltage divider bias, the current I1 flowing through R1 and R2 should be equal to or greater than 1. 10 IB 2. 3 IB 3. 2 IB 4. 4 IB Ans : 1
17. The leakage current in a silicon transistor is about ………… the leakage current in a germanium transistor 1. One hundredth 2. One tenth 3. One thousandth 4. One millionth Ans : 3
18. The operating point is also called the …………. 1. Cut off point 2. Quiescent point 3. Saturation point 4. None of the above Ans : 2
19. For proper amplification by a transistor circuit, the operating point should be located at the ………….. of the d.c. load line 1. The end point 2. Middle 3. The maximum current point 4. None of the above Ans : 2
20. The operating point ………………… on the a.c. load line 1. Also line 2. Does not lie 3. May or may not lie 4. Data insufficient Ans : 1
21. The disadvantage of voltage divider bias is that it has …………. 1. High stability factor 2. Low base current 3. Many resistors 4. None of the above Ans : 3
22. Thermal runaway occurs when ………. 1. Collector is reverse biased 2. Transistor is not biased 3. Emitter is forward biased 4. Junction capacitance is high Ans : 2
23. The purpose of resistance in the emitter circuit of a transistor amplifier is to …………. 1. Limit the maximum emitter current 2. Provide base-emitter bias 3. Limit the change in emitter current 4. None of the above Ans : 3
24. In a transistor amplifier circuit VCE = VCB + …………….. 1. VBE 2. 2VBE 3. 5 VBE 4. None of the above Ans : 1
25. The base resistor method is generally used in ……… 1. Amplifier circuits 2. Switching circuits 3. Rectifier circuits 4. None of the above Ans : 2
26. For germanium transistor amplifier, VCE should ………….. for faithful amplification 1. Be zero 2. Be 0.2 V 3. Not fall below 0.7 V 4. None of the above Ans : 3
27. In a base resistor method, if the value of ß changes by 50, then collector current will change by a factor ……… 1. 25 2. 50 3. 100 4. 200 Ans : 2
28. The stability factor of a collector feedback bias circuit is ……….. that of base resistor bias. 1. The same as 2. More than 3. Less than 4. None of the above Ans : 3
29. In the design of a biasing circuit, the value of collector load RC is determined by ………… 1. VCE consideration 2. VBE consideration 3. IB consideration 4. None of the above Ans : 1
30. If the value of collector current IC increases, then the value of VCE ………… 1. Remains the same 2. Decreases 3. Increases 4. None of the above Ans : 2
31. If the temperature increases, the value of VCE ………… 1. Remains the same 2. Is increased 3. Is decreased 4. None of the above Ans : 3
32. The stabilisation of operating point in potential divider method is provided by ………. 1. RE consideration 2. RC consideration 3. VCC consideration 4. None of the above Answer: 1
33. The value of VBE ……………. 1. Depends upon IC to moderate extent 2. Is almost independent of IC 3. Is strongly dependant on IC 4. None of the above Ans : 2
34. When the temperature changes, the operating point is shifted due to ……. 1. Change in ICBO 2. Change in VCC 3. Change in the values of circuit resistance 4. None of the above Ans : 1
35. The value of stability factor for a base resistor bias is ………… 1. RB (ß+1) 2. (ß+1)RC 3. (ß+1) 4. 1-ß Ans : 3
36. In a particular biasing circuit, the value of RE is about ……… 1. 10 kO 2. 1 MO 3. 100 kO 4. 800 O Ans : 4
37. A silicon transistor is biased with base resistor method. If ß=100, VBE =0.7 V, zero signal collector current IC = 1 mA and VCC = 6V , what is the value of the base resistor RB? 1. 105 kO 2. 530 kO 3. 315 kO 4. None of the above Ans : 2
38. In voltage divider bias, VCC = 25 V; R1 = 10 kO; R2 = 2.2 V ; RC = 3.6 V and RE =1 kO. What is the emitter voltage? 1. 7 V 2. 3 V 3. 5 V 4. 8 V Ans : 4
39. In the above question (Q38.) , what is the collector voltage? 1. 3 V 2. 8 V 3. 6 V 4. 7 V Ans : 1
40. In voltage divider bias, operating point is 3 V, 2 mA. If VCC = 9 V, RC = 2.2 kO, what is the value of RE ? 1. 2000 O 2. 1400 O 3. 800 O 4. 1600 O Ans : 3 TRANSISTORS 1. A transistor has ………………… 1. One pn junction 2. Two pn junctions 3. Three pn junctions 4. Four pn junctions ANS : 2
2. The number of depletion layers in a transistor is ………… 1. four 2. three 3. one 4. two ANS : 4
3. The base of a transistor is ………….. doped 1. heavily 2. moderately 3. lightly 4. none of the above ANS : 3 TRANSISTORS Questions and Answers pdf
4. The element that has the biggest size in a transistor is ……………….. 1. collector 2. base 3. emitter 4. collector-base-junction ANS : 1
5. In a pnp transistor, the current carriers are …………. 1. acceptor ions 2. donor ions 3. free electrons 4. holes ANS : 4
6. The collector of a transistor is …………. doped 1. heavily 2. moderately 3. lightly 4. none of the above ANS : 2
7. A transistor is a …………… operated device 1. current 2. voltage 3. both voltage and current 4. none of the above ANS : 1
8. In a npn transistor, ……………. are the minority carriers 1. free electrons 2. holes 3. donor ions 4. acceptor ions ANS : 2
9. The emitter of a transistor is ………………… doped 1. lightly 2. heavily 3. moderately 4. none of the above ANS : 2
10. In a transistor, the base current is about ………….. of emitter current 1. 25% 2. 20% 3. 35 % 4. 5% ANS : 4
11. At the base-emitter junctions of a transistor, one finds …………… 1. a reverse bias 2. a wide depletion layer 3. low resistance 4. none of the above ANS : 3
12. The input impedance of a transistor is …………. 1. high 2. low 3. very high 4. almost zero ANS : 2
13. Most of the majority carriers from the emitter ……………….. 1. recombine in the base 2. recombine in the emitter 3. pass through the base region to the collector 4. none of the above ANS :3
14. The current IB is ………… 1. electron current 2. hole current 3. donor ion current 4. acceptor ion current ANS : 1
15. In a transistor ……………….. 1. IC = IE + IB 2. IB = IC + IE 3. IE = IC – IB 4. IE = IC + IB ANS : 4
16. The value of a of a transistor is ………. 1. more than 1 2. less than 1 3. 1 4. none of the above ANS : 2
17. IC = aIE + …………. 1. IB 2. ICEO 3. ICBO 4. ßIB ANS : 3
18. The output impedance of a transistor is …………….. 1. high 2. zero 3. low 4. very low ANS : 1
19. In a tansistor, IC = 100 mA and IE = 100.2 mA. The value of ß is ………… 1. 100 2. 50 3. about 1 4. 200 ANS : 4
20. In a transistor if ß = 100 and collector current is 10 mA, then IE is ………… 1. 100 mA 2. 100.1 mA 3. 110 mA 4. none of the above ANS : 2
21. The relation between ß and a is ………….. 1. ß = 1 / (1 – a ) 2. ß = (1 – a ) / a 3. ß = a / (1 – a ) 4. ß = a / (1 + a ) ANS : 3
22. The value of ß for a transistor is generally ……………….. 1. 1 2. less than 1 3. between 20 and 500 4. above 500 ANS : 3
23. The most commonly used transistor arrangement is …………… arrangement 1. common emitter 2. common base 3. common collector 4. none of the above ANS : 1
24. The input impedance of a transistor connected in …………….. arrangement is the highest common emitter common collector common base none of the above ANS : 2 25. The output impedance of a transistor connected in ……………. arrangement is the highest 1. common emitter 2. common collector 3. common base 4. none of the above ANS : 3
26. The phase difference between the input and output voltages in a common base arrangement is ……………. 1. 180o 2. 90o 3. 270o 4. 0o ANS : 4
27. The power gain in a transistor connected in ……………. arrangement is the highest 1. common emitter 2. common base 3. common collector 4. none of the above ANS : 1
28. The phase difference between the input and output voltages of a transistor connected in common emitter arrangement is ……………… 1. 0o 2. 180o 3. 90o 4. 270o ANS : 2
29. The voltage gain in a transistor connected in ………………. arrangement is the highest 1. common base 2. common collector 3. common emitter 4. none of the above ANS : 3
30. As the temperature of a transistor goes up, the base-emitter resistance …………… 1. decreases 2. increases 3. remains the same 4. none of the above ANS : 1
31. The voltage gain of a transistor connected in common collector arrangement is ……….. 1. equal to 1 2. more than 10 3. more than 100 4. less than 1 ANS : 4
32. The phase difference between the input and output voltages of a transistor connected in common collector arrangement is ……………… 1. 180o 2. 0o 3. 90o 4. 270o ANS : 2
33. IC = ß IB + ……….. 1. ICBO 2. IC 3. ICEO 4. aIE ANS : 3
34. IC = [a / (1 – a )] IB + …………. 1. ICEO 2. ICBO 3. IC 4. (1 – a ) IB ANS : 1
35. IC = [a / (1 – a )] IB + […….. / (1 – a )] 1. ICBO 2. ICEO 3. IC 4. IE ANS : 1
36. BC 147 transistor indicates that it is made of ………….. 1. germanium 2. silicon 3. carbon 4. none of the above ANS : 2
37. ICEO = (………) ICBO 1. ß 2. 1 + a 3. 1 + ß 4. none of the above ANS : 3
38. A transistor is connected in CB mode. If it is not connected in CE mode with same bias voltages, the values of IE, IB and IC will ………….. 1. remain the same 2. increase 3. decrease 4. none of the above ANS : 1
39. If the value of a is 0.9, then value of ß is ……….. 1. 9 2. 0.9 3. 900 4. 90 ANS : 4
40. In a transistor, signal is transferred from a …………… circuit 1. high resistance to low resistance 2. low resistance to high resistance 3. high resistance to high resistance 4. low resistance to low resistance ANS : 2
41. The arrow in the symbol of a transistor indicates the direction of …………. 1. electron current in the emitter 2. electron current in the collector 3. hole current in the emitter 4. donor ion current ANS : 3
42. The leakage current in CE arrangement is ……………. that in CB arrangement 1. more than 2. less than 3. the same as 4. none of the above ANS : 1
43. A heat sink is generally used with a transistor to ………… 1. increase the forward current 2. decrease the forward current 3. compensate for excessive doping 4. prevent excessive temperature rise ANS : 4
44. The most commonly used semiconductor in the manufacture of a transistor is …………. 1. germanium 2. silicon 3. carbon 4. none of the above ANS : 2
45. The collector-base junction in a transistor has …………….. 1. forward bias at all times 2. reverse bias at all times 3. low resistance 4. none of the above ANS : 2 SEMICONDUCTOR DIODE 1. A crystal diode has ……… 1. one pn junction 2. two pn junctions 3. three pn junctions 4. none of the above ANS: 1
2. A crystal diode has forward resistance of the order of …………… 1. kΩ 2. Ω 3. MΩ 4. none of the above ANS: 2
3. If the arrow of crystal diode symbol is positive w.r.t. bar, then diode is ………….. biased. 1. forward 2. reverse 3. either forward or reverse 4. none of the above ANS: 1
4. The reverse current in a diode 1. kA 2. mA 3. μA 4. A ANS: 3
5. The forward voltage drop across a silicon diode is about ………………… 1. 2.5 V 2. 3 V 3. 10 V 4. 0.7 V ANS: 4
6. A crystal diode is used as …………… 1. an amplifier 2. a rectifier 3. an oscillator 4. a voltage regulator ANS: 2
7. The d.c. resistance of a crystal diode is ………….. its a.c. resistance 1. the same as 2. more than 3. less than 4. none of the above ANS: 3
8. An ideal crystal diode is one which behaves as a perfect ……….. when forward biased. 1. conductor 2. insulator 3. resistance material 4. none of the above ANS: 1
9. The ratio of reverse resistance and forward resistance of a germanium crystal diode is about …………. 1. 1 : 1 2. 100 : 1 3. 1000 : 1 4. 40,000 : 1 ANS: 4
10. The leakage current in a crystal diode is due to ……………. 1. minority carriers 2. majority carriers 3. junction capacitance 4. none of the above ANS: 1
11. If the temperature of a crystal diode increases, then leakage current ……….. 1. remains the same 2. decreases 3. increases 4. becomes zero ANS: 3
12. The PIV rating of a crystal diode is ………….. that of equivalent vacuum diode 1. the same as 2. lower than 3. more than 4. none of the above ANS: 2
13. If the doping level of a crystal diode is increased, the breakdown voltage…………. 1. remains the same 2. is increased 3. is decreased 4. none of the above ANS: 3
14. The knee voltage of a crystal diode is approximately equal to …………. 1. applied voltage 2. breakdown voltage 3. forward voltage 4. barrier potential ANS: 4
15. When the graph between current through and voltage across a device is a straight line, the device is referred to as ………………. 1. linear 2. active 3. nonlinear 4. passive ANS: 1
16. When the crystal current diode current is large, the bias is ………… 1. forward 2. inverse 3. poor 4. reverse ANS: 1
17. A crystal diode is a …………… device 1. non-linear 2. bilateral 3. linear 4. none of the above ANS: 1
18. A crystal diode utilises …………….. characteristic for rectification 1. reverse 2. forward 3. forward or reverse 4. none of the above ANS: 2
19. When a crystal diode is used as a rectifier, the most important consideration is ……….. 1. forward characteristic 2. doping level 3. reverse characteristic 4. PIC rating ANS: 4
20. If the doping level in a crystal diode is increased, the width of depletion layer……….. 1. remains the same 2. is decreased 3. in increased 4. none of the above ANS: 3
21. A zener diode has ……….. 1. one pn junction 2. two pn junctions 3. three pn junctions 4. none of the above ANS: 1
22. A zener diode is used as ……………. 1. an amplifier 2. a voltage regulator 3. a rectifier 4. a multivibrator ANS: 2
23. The doping level in a zener diode is …………… that of a crystal diode 1. the same as 2. less than 3. more than 4. none of the above ANS: 3
24. A zener diode is always ………… connected. 1. reverse 2. forward 3. either reverse or forward 4. none of the above ANS: 1
25. A zener diode utilizes ……….. characteristics for its operation. 1. forward 2. reverse 3. both forward and reverse 4. none of the above ANS: 2
26. In the breakdown region, a zener didoe behaves like a …………… source. 1. constant voltage 2. constant current 3. constant resistance 4. none of the above ANS: 1
27. A zener diode is destroyed if it………….. 1. is forward biased 2. is reverse biased 3. carrier more than rated current 4. none of the above ANS: 3
28. A series resistance is connected in the zener circuit to……….. 1. properly reverse bias the zener 2. protect the zener 3. properly forward bias the zener 4. none of the above ANS: 2
29. A zener diode is …………………. device 1. a non-linear 2. a linear 3. an amplifying 4. none of the above ANS: 1
30. A zener diode has ………….. breakdown voltage 1. undefined 2. sharp 3. zero 4. none of the above ANS: 2
31. ……………. rectifier has the lowest forward resistance 1. solid state 2. vacuum tube 3. gas tube 4. none of the above ANS: 1
32. Mains a.c. power is converted into d.c. power for …………….. 1. lighting purposes 2. heaters 3. using in electronic equipment 4. none of the above ANS: 3
33. The disadvantage of a half-wave rectifier is that the………………. 1. components are expensive 2. diodes must have a higher power rating 3. output is difficult to filter 4. none of the above ANS: 3
34. If the a.c. input to a half-wave rectifier is an r.m.s value of 400/√2 volts, then diode PIV rating is …………………. 1. 400/√2 V 2. 400 V 3. 400 x √2 V 4. none of the above ANS: 2
35. The ripple factor of a half-wave rectifier is ………………… 1. 2 2. 1.21 3. 2.5 4. 0.48 ANS: 4
36. There is a need of transformer for ……………….. 1. half-wave rectifier 2. centre-tap full-wave rectifier 3. bridge full-wave rectifier 4. none of the above ANS: 2
37. The PIV rating of each diode in a bridge rectifier is ……………… that of the equivalent centre- tap rectifier 1. one-half 2. the same as 3. twice 4. four times ANS: 1
38. For the same secondary voltage, the output voltage from a centre-tap rectifier is ………… than that of bridge rectifier 1. twice 2. thrice 3. four time 4. one-half ANS: 4
39. If the PIV rating of a diode is exceeded, ……………… 1. the diode conducts poorly 2. the diode is destroyed 3. the diode behaves like a zener diode 4. none of the above ANS: 2
40. A 10 V power supply would use …………………. as filter capacitor. 1. paper capacitor 2. mica capacitor 3. electrolytic capacitor 4. air capacitor ANS: 3
41. A 1,000 V power supply would use ……….. as a filter capacitor 1. paper capacitor 2. air capacitor 3. mica capacitor 4. electrolytic capacitor ANS: 1
42. The ……………….. filter circuit results in the best voltage regulation 1. choke input 2. capacitor input 3. resistance input 4. none of the above ANS: 1
43. A half-wave rectifier has an input voltage of 240 V r.m.s. If the step-down transformer has a turns ratio of 8:1, what is the peak load voltage? Ignore diode drop. 1. 27.5 V 2. 86.5 V 3. 30 V 4. 42.5 V ANS: 4
44. The maximum efficiency of a half-wave rectifier is ……………….. 1. 40.6 % 2. 81.2 % 3. 50 % 4. 25 % ANS: 1
45. The most widely used rectifier is ………………. 1. half-wave rectifier 2. centre-tap full-wave rectifier 3. bridge full-wave rectifier 4. none of the above ANS: 3 ANALOG ELECTRONICS 1. The early effect in a bipolar junction transistor is caused by A. fast turn-on B. fast turn-off C. large collector-base reverse bias D. large emitter-base forward bias
2. MOSFET can be used as a A. current controlled capacitor B. voltage controlled capacitor C. current controlled inductor D. voltage controlled inductors
3. Thermal runaway is not possible in FET because as the temperature of FET increases A. the mobility decreases B. the transconductance increases C. the drain current increases D. none of the above
4. A source follower using an FET usually has a voltage gain which is A. greater than +100 B. slightly less than unity but positive C. exactly unity but negative D. about -10
5. A differential amplifier has a differential gain of 20,000 . CMRR=80 dB. The common mode gain is given by A. 2 B. 1 C. 1/2 D. 0
6. The approximate input impedance of the OPAMP circuit which has Ri=10k,Rf=100k,RL=10k A. ∞ B.120k C.110k D.10k
7. An OPAMP has a slew rate of 5 V/µ S .The largest sine wave O/P voltage possible at a frequency of 1MHZ is A. 10 volts B. 5 volts C. 5/3 volts D.5/2 volts
8. A change in the value of the emitter resistance Re in a differential amplifier A. affects the difference mode gain Ad B. affects the common mode gain Ac C. affects both Ad and Ac D. does not affect either Ad or Ac
9. A differential amplifier is invariably used in the i/p stage of all OP-AMPs. This is dome basically to provide the OP-AMPs with a very high A.CMRR B. bandwidth C. slew rate D. open-loop gain
10. The effective channel length of a MOSFET in a saturation decreases with increase in A. gate voltage B. drain voltage C. source voltage D. body voltage
11. Which of the following is not associated with a p-n junction A. junction capacitance B. charge storage capacitance C. depletion capacitance D. channel length modulation
12. In a p-n junction diode under reverse bias , the magnitude of electric field is maximum at A. the edge of the depletion region on the p-side B. the edge of the depletion region on the n-side C. the p-n junction D. the center of the depletion region on the n-side
13. An n- channel JFET has IDSS=2mA,and Vp=-4v.Its transconductance gm=in mA/V)for an applied gate to source voltage VGS=-2v is A.0.25 B.0.5 C.0.75 D.1
14. In a common emitter, unbypassed resister provides A. voltage shunt feedback B. current series feedback C. negative voltage feedback D. positive current feedback
15. A constant current signal across a parallel RLC circuits gives an o/p of 1.4v at the signal frequency of 3.89KHZ and 4.1KHZ .At the frequency of 4KHZ,the o/p voltage will be A.1 v B. 2v C.1.4v D.2.8v
16. Class AB operation is often used in power large signal) amplifiers in order to A. gets maximum efficiency B. removes even harmonics C. overcome a crossover distortion D. reducing collector dissipation
17. The bandwidth of an RF tuned amplifier is dependent on A. Q –factor of the tuned o/p circuit B. Q –factor of the tuned i/p circuit C. Quiescent operating point D. Q-factor of the o/p and i/p circuits as well as quiescent operating point
18. If =0.98 ,Ico=6µA and Iβ=100µA for a transistor,then the value of Ic will be A.2.3mA B.3.2mA C.4.6 mA D.5.2mA
19. The MOSFET switch in its on-state may be considered equivalent to A. resistor B. inductor C. capacitor D. battery
20. Most of the linear ICs are based on the two-transistor differential amplifier because of its A. input voltage dependent linear transfer characteristic B. high voltage gain C. high input resistance D. high CMRR
21. Negative feedback in an amplifier A. Reduces gain B. Increase frequency &phase distortion C. Reduces bandwidth D. Increases noise
22. A dc power supply has no-load voltage of 30v,and a full-load voltage of 25v at full-load current of 1A.Its output resistance & load regulation ,respectively are A. 5 Ω & 20 % B. 25 Ω & 20 % C. 5 Ω & 16.7 % D. 25 Ω & 16.7 %
23. The current gain of a bipolar transistor drops at high frequencies because of A. Transistor capacitances B. High current effects in the base C. Parasitic inductive elements D. The early effect
24. The ideal OP-AMP has the following characteristics. A. Ri=∞ ,A=∞ ,R0=0 B. Ri=0 ,A=∞ ,R0=0 C. Ri=∞ ,A=∞ ,R0=∞ D. Ri=0 ,A=∞ ,R0=∞
25. An npn BJT has gm=38mA/v, cµ =10¯14 F, cπ =10¯13F and DC current gain β0=90.For this transistor fT & fβ are A. fT =1.64 x 108 Hz & fβ = 1.47 x 1010 Hz. B. fT =1.47 x 1010 Hz & fβ = 1.64 x 108 Hz C. fT =1.33 x 1012 Hz & fβ = 1.47 x 1010 Hz D. fT =1.47 x 1010 Hz & fβ = 1.33 x 1012 Hz
26. A 741-type OP-AMP has a gain-bandwidth product of 1MHz.A non-inverting amplifier using this op-amp & having a voltage gain of 20db will exhibit -3db bandwidth of A. 50 KHz B. 100 KHz C. 1000/17 KHz D. 1000/7.07 KHz
27. An amplifier using an op-amp with slew rate SR=1v/µsec has a gain of 40db.if this amplifier has to faithfully amplify sinusoidal signals from dc to 20 KHz without introducing any slew-rate induced distortion, then the input signal level must not exceed A. 795mV B. 395mV C. 795 mV D. 39.5mV
28. In the differential voltage gain & the common mode voltage gain of a differential amplifier are 48db &2db respectively, then its common mode rejection ratio is A.23dB B.25dB C. 46dB D. 50dB
29. Generally, the gain of a transistor amplifier falls at high frequencies due to the A. Internal Capacitance of the device B. Coupling capacitor at the input C. Skin effect D. Coupling capacitor at the output
30. An amplifier without feedback has a voltage gain of 50,input resistance os 1 KΩ & Output resistance of 2.5KΩ.The input resistance of the current-shunt negative feedback amplifier using the above amplifier with a feedback factor of 0.2 is A. 1/11KΩ B. 1/5KΩ C. 5KΩ D. 11KΩ
31. The action of JFET in its equivalent circuit can best be represented as a A. Current controlled Current source B. Current controlled voltage source C. Voltage controlled voltage source D. voltage controlled current source
32. Three identical amplifiers with each one having a voltage gain of 50,input resistance of 1KΩ & output resistance of 250, are cascaded. The open circuit voltage gain of combined amplifier is A. 49dB B. 51dB C. 98dB D. 102dB
33. An ideal OP-AMP is an ideal A. Current controlled Current source B. Current controlled voltage source C. Voltage controlled voltage source D. voltage controlled current source
34. In a full-wave rectifier using two ideal diodes, Vdc & Vm are the dc & peak values of the voltage respectively across a resistive load. If PIV is the peak inverse voltage of the diode, then the appropriate relationships for this rectifier is. A. Vdc = Vm/π, PIV=2Vm B. Vdc = 2Vm/π, PIV=2vm C. Vdc = 2Vm/π, PIV=Vm D. Vdc = Vm/π, PIV=Vm
35. The cascade amplifier is a multistage configuration of A. CC-CB . B. CE-CB C. CB-CC D. CE-CC
36. The current gain of a BJT is A. gm r0 B. gm / r0 C. gm rπ D. gm /rπ
37. The most commonly used amplifier in sample & hold circuits is A. A unity gain non-inverting amplifier B. A unity gain inverting amplifier C. An inverting amplifier with a gain of 10 D. An inverting amplifiers with a gain of 100
38. To prevent a DC return between source and load, it is necessary to use A. resistor between source and load B. inductor between source and load C. capacitor between source and load D. either A. or B.
39. Introducing a resistor in the emitter of a common amplifier stabilizes the dc operating point against variations in A. Only the temperature B. only the β of the transistor C. Both Temperature & β D. None of the above
40. Voltage Series feedback also called series-shunt feedback) results in A. Increase in both input & output impedances B. Decreases in both input & output impedances C. Increase in input impedance & decreases in output impedance D. Decrease in input impedance & increase in output impedance
41. The encapsulation of transistor is necessary for A. preventing radio interference B. preventing photo-emission effects C. avoiding loss of free electrons D. mechanical ruggedness Answer: D
42. In a transistor leakage current mainly depends on A. doping of base B. size of emitter C. rating of transistor D. temperature Answer: D
43. In a CB amplifier the maximum efficiency could be A. 99% B. 85% C. 50% D. 25% Answer: D
44. When a transistor is connected in common emitter mode, it with have A. negligible input resistance and high output resistance B. high input resistance and low output resistance C. medium input resistance and high output resistance D. low input resistance as well as output resistance Answer: C
45. In all base driver amplifiers A. ac collector voltage is 180° out of phase with ac base voltage B. ac emitter voltage is 180° out of phase with ac base voltage C. ac collector voltage is in phase with ac base voltage D. none of the above Answer: A
46. The horizontal intercept of dc load line is the same as ideal A. cut off point B. saturation point C. operating point D. quasi saturation point Answer: A
47. In deriving ac equivalent circuit for an amplifier circuit we short circuit A. all resistors B. all transistors C. all inductors D. all capacitors Answer: D
48. Which of the following statements is false? A. Push pull signals are equal and opposite in phase B. Class AB operation cannot be used for a push pull audio power output phase C. A push pull output transformer has a centre-tapped primary D. All of the above Answer: B
49. Which of the following amplifier circuit using junction transistor has the best gain? A. Common base B. Common emitter C. Common collector D. All have the same gain Answer: B
50. In an op-amp differentiator A. the amplitude of output is proportional to rate of change of input B. the amplitude of output is proportional to input C. output occurs when input is finite and constant D. polarity of input and output is the same Answer: A
Answers:- 1. C 2. B 3. A 4. A 5. A 6. D 7. D 8. B 9. A 10. B 11. D 12. C 13. B 14. C 15. B 16. C 17. A 18. D 19. C 20. D 21. A 22. B 23. A 24. A 25. B 26. B 27. C 28. C 29. A 30. A 31. D 32. C 33. B 34. B 35. B 36. C 37. B 38. C 39. C 40. C DIGITAL ELECTRONICS 1. In which of the following base systems is 123 not a valid number? (a) Base 10 (b) Base 16 (c)Base8 (d) Base 3 Ans:d
2. Storage of 1 KB means the following number of bytes (a) 1000 (b) 964 (c) 1024 (d) 1064 Ans:c
3. What is the octal equivalent of the binary number: 10111101 (a)675 (b)275 (c) 572 (d) 573. Ans:b
4. Pick out the CORRECT statement: (a) In a positional number system, each symbol represents the same value irrespective of its position (b) The highest symbol in a position number system as a value equal to the number of symbols in the system (c) It is not always possible to find the exact binary (d) Each hexadecimal digit can be represented as a sequence of three binary symbols. Ans:c
5. The binary code of (21.125)10 is (a) 10101.001 (b) 10100.001 (c) 10101.010 (d) 10100.111. Ans:a
6. A NAND gate is called a universal logic element because (a) it is used by everybody (b) any logic function can be realized by NAND gates alone (c) all the minization techniques are applicable for optimum NAND gate realization (d) many digital computers use NAND gates. Ans:b
7. Digital computers are more widely used as compared to analog computers, because they are (a) less expensive (b) always more accurate and faster (c) useful over wider ranges of problem types (d) easier to maintain. Ans:c
8. Most of the digital computers do not have floating point hardware because (a) floating point hardware is costly (b) it is slower than software (c) it is not possible to perform floating point addition by hardware (d) of no specific reason. Ans:a
9. The number 1000 would appear just immediately after (a) FFFF (hex) (b) 1111 (binary) (c) 7777 (octal) (d) All of the above. Ans:d
10. (1(10101)2 is (a) (37)10 (b) ( 69)10 (c) (41 )10 (d) — (5)10 Ans:a
11. The number of Boolean functions that can be generated by n variables is equal to (a) 2n (b) 22 n (c) 2n-1 (d) — 2n Ans:b
12. Consider the representation of six-bit numbers by two’s complement, one’s complement, or by sign and magnitude: In which representation is there overflow from the addition of the integers 011000 and 011000? (a) Two’s complement only (b) Sign and magnitude and one’s complement only (c) Two’s complement and one’s complement only (d) All three representations. Ans:d
13. A hexadecimal odometer displays F 52 F. The next reading will be (a)F52E (b)G52F (c)F53F (d)F53O. Ans:d
14. Positive logic in a logic circuit is one in which (a) logic 0 and 1 are represented by 0 and positive voltage respectively (b) logic 0 and, -1 are represented by negative and positive voltages respectively (c) logic 0 voltage level is higher than logic 1 voltage level (d) logic 0 voltage level is lower than logic 1 voltage level. Ans:d
15. Which of the following gate is a two-level logic gate (a) OR gate (b) NAND gate (c) EXCLUSIVE OR gate (d) NOT gate. Ans:c
16. Among the logic families, the family which can be used at very high frequency greater than 100 MHz in a 4 bit synchronous counter is (a) TTLAS (b) CMOS (c)ECL (d)TTLLS Ans:c
17. An AND gate will function as OR if (a) all the inputs to the gates are “1” (b) all the inputs are ‘0’ (c) either of the inputs is “1” (d) all the inputs and outputs are complemented. Ans:d
18. An OR gate has 6 inputs. The number of input words in its truth table are (a)6 (b)32 (c) 64 (d) 128 Ans:c
19. A debouncing circuit is (a) an astable MV (b) a bistable MV (c) a latch (d) a monostable MV. Ans:c
20. NAND. gates are preferred over others because these (a) have lower fabrication area (b) can be used to make any gate (c) consume least electronic power (d) provide maximum density in a chip. Ans:b
21. In case of OR gate, no matter what the number of inputs, a (a) 1 at any input causes the output to be at logic 1 (b) 1 at any input causes the output to be at logic 0 (c) 0 any input causes the output to be at logic 0 (d) 0 at any input causes the output to be at logic 1. Ans:a
22. The fan put of a 7400 NAND gate is (a)2TTL (b)5TTL (c)8TTL (d)10TTL Ans:d
23. Excess-3 code is known as (a) Weighted code (b) Cyclic redundancy code (c) Self-complementing code (d) Algebraic code. Ans:c
24. Assuming 8 bits for data, 1 bit for parity, I start bit and 2 stop bits, the number of characters that 1200 BPS communication line can transmit is (a)10 CPS (b)120 CPS (c) 12CPS (d) None of the above. Ans:c
25. Indicate which of the following three binary additions are correct? 1.1011 + 1010 = 10101 II. 1010 + 1101 = 10111 III. 1010 + 1101 = 11111 (a) I and II (b) II and III (c) III only (d) II and III